In this week’s post on my Slumdog’s recent need for sedation, the tranquilizer known as acepromazine was addressed in response to a round of questions. As in––Why wouldn’t you use this tried and true veterinary drug on your own dog?
When I offered my answer, I received a comment urging me to be more clear about “ace” so that pet owners wouldn’t get a one-sided view of this popular drug. In response, I thought it wise to provide a more complete rendering of the issues involved in its usage––especially since acepromazine is veterinary medicine’s go-to tranquilizer.
This drug is used in a variety of ways in veterinary medicine. Here are the most commonly applied indications in cat and dog medicine:
- as an oral sedative for travel, during storms and before grooming or veterinary visits
- as an injectable tranquilizing agent to address aggressive, fractious or disruptive behaviors in hospital settings
- in small doses (and typically in combination with an opiate), as an injectable anesthetic pre-medication
- in small doses in combination with pain relievers post operatively to enhance the effect or lower the dose of the analgesic
In the last two cases, I employ acepromazine often (though by no means always). Pre-op, it’s used to lower the dose of anesthetic induction agents to follow, lower blood pressure slightly, reduce the potential for arrhythmias (abnormal heart rhythms) and vomiting, and to confer mild relaxation prior to the procedure. Post-op, its synergistic effects with drugs like opiates mean that a small dose of acepromazine makes the pain relievers more effective in smaller doses.
That’s why I like ace. But I don’t tend to reach for acepromazine in the first two instances (for which sedation is the ultimate goal). I happen to believe the side effects related to acepromazine outweigh its benefits in these cases given that plenty of other drugs provide safer, more comfortable alternatives if a quiet animal is your goal. Here’s the down-side of its uses as a tranquilizer/sedative, as presented by Plumb’s Veterinary Drug Handbook (which I urge you all to buy):
- It reduces the seizure threshold in animals and can bring on seizures in pets predisposed to them (epileptics, brain tumor patients, etc.).
- At the labeled therapeutic dose indicated for sedation/tranquilization, it can cause profound hypotension (low blood pressure) in some animals.
- Giant breed dogs and sighthounds can experience extremely deep sedation and prolonged recovery times (indeed, I once saw a greyhound sleep like the dead for two days after half the normal dose was administered intramuscularly)
- “Acepromazine should be used very cautiously as a restraining agent in aggressive dogs, as it may make the animal more prone to startle and react to noises or other sensory inputs.”
- In fact, aggressive dogs can sometimes become more aggressive after receiving acepromazine. It's posited that the dysphoria associated with this class of tranquilizing drugs is responsible for this.
- “Acepromazine has no analgesic effects.” It does not relieve pain. (Though this is not really a down-side unless you’re performing a procedure without other pain relievers on board.)
- Despite its anti-arrhythmia qualities, it's been observed that boxers can suffer life-threatening arrhythmias with acepromazine––albeit rarely. Veterinarians must always be mindful of this when using ace in boxers.
Further, Plumb’s goes on to explain that,
“The use of acepromazine as a sedative/tranquilizer in the treatment of adverse behaviors in dogs or cats has largely been supplanted by newer, effective agents, that have fewer adverse effects.
Moreover,
“Its use for sedation during travel is controversial, and many no longer recommend drug therapy for this purpose.”
It’s also believed that acepromazine, used freely for noise phobia, may actually heighten pets’ sensitivity to noise. For this reason, one of my local behaviorists is especially opposed to its use during storm or fireworks season.
All good points. But for me, the larger issue is this: With acepromazine, the potential for dysphoria (an unhappy feeling) is high. Though we have no way of confirming this (except by inference, as in the case of heightened aggression in dogs who receive ace), we do know that similar tranquilizers in humans have fallen out of favor due to their dysphoric effects on people.
Consider Thorazine (chlorpromazine): This drool-on-yourself, One Flew Over the Cuckoo’s Nest kind of tranquilizer was once ubiquitous in human psych wards. Though this acepromazine-like drug is still used, it’s not exactly a kind drug when used in big, human-stopping doses. Still, nothing quiets a raging psychotic like Thorazine does. Same goes for acepromazine in pets. It stops them. And that’s why we like it.
Problem is, not only do we have the case of dysphoria and Thorazine to consider, we also happen to know that acepromazine causes even more profound dysphoria in humans than “Vitamin T” does. That’s why humans very rarely abuse it.
You may abhor the comparison between humans and animals in this case. After all, humans and animals don’t react the same way to all kinds of drugs. Nonetheless, neglecting to use human drug reactions as a starting point for how these drugs might theoretically act in animals seems a silly thing to do. But we do so all the time in cases where psychology is involved. As if animals might not experience similar alterations in brain chemicals in the same way...simply because we can’t ask them how they feel.
Same is true for how pain relief has historically been treated in animals, infants and children. When we can’t measure the psychological effects of pain, we’ve been––until very recently––reluctant to offer chemical relief for it.
Human and animal comparisons aside, I have a problem with acepromazine not only because of the potential for dysphoria, but because it doesn’t address the underlying problem: anxiety. Sure, it keeps staff safe, but all kinds of drugs can do that...while inducing drowsiness and offering the minimized awareness we associate with comfortable sedation in ourselves. Ace, by contrast, doesn’t necessarily achieve this.
Again, if animals are like humans, the tranquilization acepromazine offers allows for continued awareness (perhaps even heightened awareness). In fact, that’s technically the difference between a tranquilizer and a sedative. Tranquilizers, by definition, allow you to retain some awareness.
Then there’s the issue of its "overuse" as a sedative.
Acepromazine is tried and true. We’re comfortable with it. And for some reason, switching from ace to something else––even while all the research tells us it’s safer––is a stressful process for all practitioners. Knowing the ins and outs of how our favorite drug works means more safety in the short run...even though we know better choices are available when it comes to achieving a quiet animal.
That’s why, I believe, acepromazine continues to hold sway in small animal veterinary medicine for sedation. That, its low abuse potential, its relative safety, its effectiveness...and the price factor, of course. Because it’s way cheaper than alternatives like dexmedetomidine and way less “abuse-prone” than hydromorphone (a morphine-like opiate), we tend to stick to it.
But that’s not acceptable as a matter of course say some anesthesiologists and behaviorists. They point out that the very issues that make acepromazine so popular are those that lead to its abuse: grooming and boarding facilities that “ace” everything when things get noisy, veterinary hospitals that hand out ace like pez for every kind of restless pet scenario, veterinarians who ace all aggressive dogs first and ask questions later, etc.
It’s not appropriate to reach for acepromazine in these cases...perhaps not for any kind of scenario in which sedation is the goal, it’s increasingly argued. Not as long as better options are out there that can achieve the same effects more safely and with greater attention to the animal welfare issues involved.
After all, offering ace as a sedative isn't helpful to your pet if her brain doesn’t quiet down along with her body. And it's primarily on this basis that I object to ace: Sedating pets without regard for what they may experience is the height of human hubris. Especially when there's a better way.
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Ace made my TFT more aggressive;he he became an aligator! It's on his record not to give him "ace".
Moe October 22nd, 2009 01:02:36 PM
Most interesting -- this is new information to me. I used ACE for one of my grooming-phobic pooches just yesterday, without incident, but the thought of dysphoria in my girl is troubling. Anxious to see what unfolds in the comments here.
oh holland October 22nd, 2009 01:06:26 PM
My observations of how animals act and react while under different tranquilizers added to my amazement that people would abuse those drugs. After seeing many dogs that are 'aced' turn into twitchy, obviously frightened creatures who were 'trapped' by their body being stuck while their nerves and mind where ramped up, I hate that it's given out, as you, like pez, for at home use. Ace was a factor in my first greyhound's deadly reaction to other anesthesia drugs, leading to hyperthermia, seizures, and death.
And while we weren't talking about ketamine here, watching cats coming out of it (after neuters), is not pleasant. They usually seem to be having half-awake nightmares of giant rats coming to eat them, and I don't understand the 'thrill' people say it gives them.
I am so glad that none of my dogs have noise phobias, and I dread the day I ever have to dispute an ace prescription with a vet.
KateH October 22nd, 2009 01:21:34 PM
KateH: For humans, Ketamine is an acquired taste, I'm told. In very small doses it's like marijuana whereas large, "K-hole" doses are for those who enjoy being thoroughly blotto. And yes, it's a hallucinogen, too. I've known people who tried it and swore they'd never understand why anyone would give that to a cat.
Hence, the liberal use of valium along with Ketamine whenever most veterinarians employ it in cats and dogs. Valium's effective sedative properties seems to mitigate the discomfort or fear that can accompany Ketamine's naked administration.
Though I don't use it very often anymore, Ketamine does have some pain-relieving qualities to recommend it, as well. Luckily, this effect is achieved in very small doses.
Dr. Patty Khuly October 22nd, 2009 01:30:09 PM
What about valium, then? My parent's dog was on that for some time before they took him for surgery for his tracheal paralysis, and it worked great for a while at keeping him relaxed and calm about that (as I understood it, the goal was to literally keep his throat muscles relaxed). He seemed both happy and mellow, though granted he was a 12 year old retriever, so mellow was pretty par for the course. Why is that not more popular? Or is the concern that the owners would abuse it?
Caro October 22nd, 2009 02:02:47 PM
It's my understanding that ace was used as a pre-anesthetic to help prevent arrhythmias associated with halothane, but that this is no longer needed with the newer anesthetics isoflurane and sevoflurane. That doesn't mean ace might not be appropriate for the other reasons you list, but isn't its use to prevent arrhythmias outdated?
Mary Straus October 22nd, 2009 02:33:08 PM
Diazepam (Valium) can have some real down sides. My mother was addicted to it back when they handed those out to women like they were candy and saying they couldn't possibly be habit forming. Personally, I'm not a fan of the tranquilizers most of the time. Tried them once with my first Lab for travel stress. While on them was the one and only time she ever bit anyone and it was largely because she gave no warning at all; from loopy to chomp. Control freak that I am, I'd personally rather be sedated than tranquilized; nothing worse than having awareness AND slow response from body and brain. For control freaks, that's scary. I can't help but think an aggressive dog is in the same boat... Fear lends to aggressiveness; fear increased by that sense of slowed perception/response lends to sudden and exaggerated aggressiveness with the exaggerated being caused by the slow feedback loop, you don't know what you've done immediately because of the slowed perception.
"humans than "Vitamin T" does" Yep, I had to look it up and I'm still not sure which definition/connotation I should be reading in for that one :)
PJBoosinger October 22nd, 2009 03:00:33 PM
I wish more literature would remind people that the MDR1-mutant dogs don't tolerate Ace well. WSU recommends lowering the dosage 25% for heterozygous mutants (1 normal, 1 mutant copy of the gene) and by 30-50% in homozygous mutants (2 mutant copies of the gene).
The stuff written above about grooming & boarding facilities using Ace makes me very uncomfortable -- I kind of doubt the kennel staff is going to think about my dog's MDR1 status before dosing her if they're running around willy-nilly dosing noisy or agitated dogs.
kabbage October 22nd, 2009 03:04:16 PM
Some of my vets have told me that Bulldogs have a tendency to react badly to Ace as well, and were very reluctant to use it with my Lucie. I appreciate your post, though, because I forwarded it to my sister, whose dog has a seizure disorder. She gets him groomed and occasionally boards him. I suggested that she have noted in his file that he was not to be given Ace under any circumstances.
Susan October 22nd, 2009 03:14:21 PM
Mary: That's true. In "Veterinary Anesthesia and Pain Management secrets," a text by anesthesiologist Stephen A. Greene, he allows that the arrhythmia issue is cited as a reason to use ace but that this benefit no longer outweighs the risks. When halothane was more widely used, it may have been otherwise.
Dr. Patty Khuly October 22nd, 2009 03:15:32 PM
I appreciate you posting this kind of drug evaluation. It is the type of information pet owners need and the type of discussion that needs to be happening in the veterinary community.
I am also wondering what you think of the use of xylazine as a primary anesthetic in dogs.
Stefani October 22nd, 2009 03:17:25 PM
kabbage: Oops...I forgot to mention the MDR1 thing in this post. thanks for raising it. These dogs definitely experience the ace effect more profoundly. Sleep for days, sometimes.
Caro: We use plenty of injectable Valium (diazepam) but as a sedative it's not our favorite. Some of that has to do with drug abuse but mostly, it's the liver toxicity issue––especially when we're talking about serial sedation. Xanax (alprazolam), very similar to valium, seems to be largely free of the more severe hepatotoxic effects.
Problem is, some dogs will enjoy the Xanax effect too much. They seem to think it's party time when the pills come out. "Happy drunks," I call them. In these cases, you simply have to give more or pair it with another mild sedative. For Slumdog, I'm using Benadryl alongside it to enhance the sedative effect without having to give more Xanax.
Dr. Patty Khuly October 22nd, 2009 03:57:28 PM
Stefani: I also suspect dysphoria to be a potentially huge issue with xylazine as a sedative. Luckily, there are plenty of safety reasons to use it only in small doses or in drug combinations--never all by itself.
Here's a rundown.
Dr. Patty Khuly October 22nd, 2009 04:03:58 PM
I have boxers so I always request that acepromazine not be used for procedures requiring sedation or general anesthesia. Since there are safer alternatives available I do not want to risk using ace on my dog, even if the risk is low. My 7-yr old male required 2 surgeries this year, one for corneal ulcers and a TPLO. For Darwin's surgeries he received diazepam and hydromorphone as a pre-anesthetic and for x-rays he received midazolam and hydromorphone.
The veterinary opthamologist did not question my request at all. She assured me that they never use ace with boxers. On the other hand, 2 of 3 orthopedic surgeons that we saw at the vet teaching hospital seemed reluctant to take my request seriously. The first, the senior surgeon, totally brushed me off - it was up to the anesthesiologist. I firmly but politely insisted that he inform the anesthesiologist of my wishes. In the end, I got what I wanted, but I wish I wasn't made to feel like an overprotective, naive idiot. I'm not a doctor but I am a research scientist so I know what I am doing when it comes to researching information on the internet.
And this wasn't the only problem I have had with the ortho surgeons. While I am happy with the TPLO, Darwin suffered an adverse reaction to Deramaxx prescibed post-op, which resulted in impaired kidney function (thankfully reversible). All the warning the surgeons gave me had to do with adverse gastrointestinal effects and when I informed them of increased urination/water intake they made no mention of the possibility of kidney damage and did not suggest running a blood chemistry panel. I have since learned not to rely on surgeons for anything but surgery (much like in human medicine).
Karlyn October 22nd, 2009 04:07:18 PM
Thank you for addressing this topic again, Dr. Khuly. I'm glad that you broke down the uses of acepromazine into categories because that really does make a difference when you are discussing the pros and cons of any drugs. When you discuss its down-sides, though, it is very easy for the lay reader to apply those down-sides to all its uses and forget that the alternative drugs have downsides of their own so I'd still like to address some of your points.
Seizures: there is no documentation that ace lowers the seizure threshold. In fact, there are studies that show that it does not. I still avoid it IF I CAN in dogs with a history of seizures but if it is the best drug for that case, I will go ahead and use it.
I don't use the label dose for acepromazine and I don't for its alternatives either. I find the effects of one particular and recently popular sedative drug to be especially scarey at its label dose. It is an important point that a lot of the negative effects of acepromazine are related to high doses.
Which brings me to the subject of ace in greyhounds, giant breeds, and MDR1 mutant dogs. Problems are very dose related. I use a very low dose and cut that back in large dogs. I was at a panel discussion at a conference last week where one of three anesthesiologists cuts his dose a bit in greyhounds but the other two do not.
Acepromazine is actually my go-to sedative in greyhounds BECAUSE they suffer from agitation and hyperthermia. Its properties actually work well to combat those problems.
As a restraining agent for aggressive dogs: Its not my favorite but I'll use it when other drugs are contraindicated. Dogs can be startled under any sedative drugs. I have a scar on my finger from the dog that was very sedate one moment under an alternative to ace and biting me the next.
As for dysphoria: Dysphoria can happen with any sedative or analgesic drug. I find that I get it more with the benzodiazepines.
Which brings me to my last point and one you touched on in your last blog about ace. Veterinary medicine can be an art in addition to being a science. We all have our preferences. People should keep this in mind and when they discuss sedation with their vet. They should voice their concerns rather than tell the vet what should be used or not used. Neither, you, Dr. Khuly, or I are board certified in anesthesia so we don't have any better credentials than the vet down the street who may have a very good reason to disagree with either of us.
virginian October 22nd, 2009 04:43:20 PM
Also not a fan.
I've been on the teeth end of an Aussie mix who had what his vet called a "paradoxical reaction" to Ace. Errr ... sure, it that's what you want to label psychosis, go ahead.
The dog was NOT okay afterwards -- he started exhibiting intraspecific aggression that he had not prior to the Acing.
I've personally witnessed a lowering of bite threshold on Aced dogs. They act all passive and dopey until you cross the invisible line during intimate handling, and then they are mighty quick when they nail ya.
And I thank Kabbage for mentioning the MDR1 connection. Thing is, few people with a mutant/normal or mutant/mutant dog know it. It's not just a problem for purebred show collies of AKC lineage, though that gene pool is the most affected. Anything mixed with or among the collie breeds is at risk, and you don't necessarily know by looking. Is that dog part collie, or part retriever and part sighthound?
H. Houlahan October 22nd, 2009 04:47:03 PM
Ace is widely regarded by Chinese Crested owners as a drug to be avoided for our dogs, not just when the goal is sedation, but when the goal is anesthesia, as well. I know people whose dogs have had scary bad reactions with anesthesia protocols involving Ace despite successful and uneventful surgery experiences both before that scary experience, and after.
It's hard to ignore your own or your friends' personal experience, and the more different dogs that experience is repeated with, the harder it is to ignore. There may be dogs for whom this is a safe drug, but I would never want to take the chance with a Crested.
Lis October 22nd, 2009 05:40:30 PM
Dr. K - interesting that you mention diazepam's liver toxicity issues...in our "hepatic protocol", we use diazepam/butorphanol instead of ace/butorphanol. Hmmm...
Before discovering the best way to deal with my dog's extreme thunder phobia (turns out she does best if left outdoors in her doghouse...never would have imagined she felt safer in there as opposed to inside my home!), she got aced 30-60 minutes before the storm rolled in, and in regular intervals until it rolled out. I didn't particularly like doing it - you could totally tell that she was still freaked but just too drunk to do anything about it. But alprazolam didn't touch her, and I couldn't deal with her injuring herself - breaking nails, bloodying up her mouth chewing through doors, etc. So as many drawbacks as the drug has, I think most clients get to a point where they just need the dog to STOP. And I can understand that, much as I try to educate people about the drug's pros/cons.
With regards to drugs used as premedicants, I think the veterinarian's familiarity and experience with a particular drug is far more relevant to the animal's safety than just about anything the reference texts may asterisk, the possible exception being the pet who has previously experienced a negative response. It's sometimes difficult to relay that to a client without them thinking they're being brushed off.
anna October 22nd, 2009 05:44:35 PM
Anna, is the breed-specific knowledge of informed, knowledgable owners relevant? Or does the veterinarian's familiarity and experience with a particular drug trump the shared experience and knowledge of the owners of a breed the veterinarian may never have treated before?
Lis October 22nd, 2009 06:21:17 PM
We are being taught that the "ace lowers the seizure threshold" idea is a myth, based on an old study of a different phenothiazine used at much-higher-than-therapeutic doses.
Megan October 22nd, 2009 06:49:10 PM
Lis - FWIW, my comment wasn't intended as a response to yours - yours posted while I was typing mine.
Also, I've seen many Cresteds do just fine with ace on board in the few years I've been working in clinics. But that's just my anecdotal experience - as are the experiences of most breeders, regardless of how well-informed they are.
I think veterinarians should practice evidence-based medicine - if there is a peer-reviewed, established contraindication or high-risk group, then I expect them to act accordingly. Otherwise, I think it's most important for the veterinarian to have experience with the drugs they are using. Every drug has side effects, but they can be mitigated if the veterinarian can anticipate them. Of course, if they are familiar with a substitute that's appropriate for the case, that may be slightly less risky (even anecdotally), then I'd expect them to choose that substitute - why not?
anna October 22nd, 2009 06:49:55 PM
"evidence-based medicine" includes personal experience, as I'm sure any vet in practice for a decade or more will attest. Excluding the evidence presented by owners is ignoring significant evidence. Why wait for peer review generalities when the specifics are before you? No doubt vets need to be familiar with the drugs but they should also be familiar with the variations in the gene pool as well. (I mean, when it's been proven that there is a very statistically relevant variation of normal lab ranges between Asians and Anglo-Saxons, how do we argue that major differences don't exist between a Chihuahua and a Great Dane?) As for mitigating, well, that's not as good as preventing in my book. My vet recently "mitigated" the damage she and her staff did to my Shiba. They mitigated to the best of their ability. However, damage to a body has a cumulative effect so the damage is done and not truly mitigated, it never is...
PJBoosinger October 22nd, 2009 08:12:54 PM
Megan: I find that interesting...especially given that this class of drugs is generally considered to be seizure-disorder safe in humans. Never saw a seizure reaction in my ace patients but always kept the possibility in mind, of course.
Dr. Patty Khuly October 22nd, 2009 08:17:33 PM
Anna, Megan, et al: The interesting thing about acepromazine is that most of the research is VERY old. Much of it cites seizure issues, arrythmias and hypotension studies conducted back in the 60s and 70s. If you look at the indicated doses in the literature you'd be shocked at their high levels.
Meanwhile, acepromazine remains the most commonly used "sedative" in vet medicine. It's my opinion that we continue to use it because it suits our purposes...not necessarily because it meets our ultimate goals.
Dr. Patty Khuly October 22nd, 2009 08:25:54 PM
""evidence-based medicine" includes personal experience, as I'm sure any vet in practice for a decade or more will attest. Excluding the evidence presented by owners is ignoring significant evidence."
Well, I suppose we'll have to, as usual, agree to disagree. :)
anna October 22nd, 2009 08:38:18 PM
As groomers in BC, we have no authority to give an animal "ace" or any other medication. Furthermore, we never would. We don't have the medical training to know if there is a problem developing. Recently, we allowed a dog who has been seen by her vet that morning, weighed for an appropriate dosage, come in on "ace" for her grooming. She was beyond loopy. Unable to hold herself vertical on the table, the grooming noose almost became a real noose. She did not weigh enough to trigger the safety release. This was enough to convince us we will not groom under sedation no matter who administered the drug.
In the future, we'll be telling our clients "If you believe your pet needs sedation for a groom then either have it done at the vet clinic or request a mobile groomer to meet you there - we do not feel comfortable participating with that in our shop." Humanity before vanity? Sure. We also heard this week from a client that her sister-in-law's dog died from a heart attack while being groomed. She had tried it herself, though it took four people to hold the dog down enough to complete the task, which she wasn't comfortable with.
We have asked our local vets for their best recommendations about this issue, and none seems to want to go on the record with an opinion. It is becoming more of a concern for us for as the number of clients grows, it seems that the number of times we face clients who have dogs who cannot tolerate grooming is also growing.
BevBC October 22nd, 2009 09:56:17 PM
BevBC, I had a long haired cat that needed bathing and grooming (she had very full 'pantaloons' that would become encrusted with excrement if not shaved down) as she got older and less flexible. I found a wonderful groomer. The first visit I was told to leave the cat all day as she liked to work very slowly and for short periods of time until the cat got used to it. Turns out she didn't need the whole day and called me after 45 minutes to say "you can pick her up". I was in a panic as I thought the cat freaked and she wasn't able to do any grooming at all. Turns out, my baby loved the attention and was a breeze to bath, brush and shave. Her brother on the other hand...let's just say that our vet learned how to sedate and shave a butt really well. We had to take him to the vet because the groomer would NOT, under any circumstances, sedate an animal. The point is that the pet needs to become comfortable with grooming. It didn't hurt that they were used to being brushed and having their claws clipped at home either.
Donna October 22nd, 2009 11:10:01 PM
Thank you for writing this article! I have a client that uses ace to deal with her Min Pin with out giving it a second thought. While we are taking steps in training to deal with his issues, this article is definitely one that i will pass on to her for those moments when she's extremely frustrated and feels the urge to return to dosing him.
I've never been a fan of treating behavior issues with drugs unless absolutely necessary. There are many out there that don't think this way.
emily October 23rd, 2009 02:12:01 AM
Anna and Virginian: I agree that comfort with drug protocols is crucial. But that alone is no reason for not trying new combinations in more controlled settings (for example, on a slower day when plenty of tech support is immediately available).
If our evidence-based medicine is to serve any purpose, it's to push us to evolve as a profession with respect to safer combinations. Kitty magic, microdosed dexdomitor (along with hydromorphone or buprenorphine), propofol after small dose pre-ops (which may or may not include the BAG protocol), for example. All have replaced my heavier hand with ace, ketamine and straight telazol. But not without a struggle. I agree that it's necessarily stressful to change our trusted methods.
It's been the same with our pain protocols. We don't give our older clinicians a pass just because they're uncomfortable with these meds. Not when we now know enough about them to understand how critical they are––and how safe.
Yes, it's an art and a science. But the art needs to include a well-reasoned approach based on the science or else we're doomed to stick with outmoded approaches that will eventually get us into trouble (reference the old-timer vet who used no pain meds for his orthopedic procedures and suffered the loss of his license for his intransigence).
I know it sounds as if I'm getting on my high horse and using my bully pulpit to make things tough for my colleagues. At least I'm doing so using what I hope is well-referenced information so that people can make up their own minds. Sure, I have strong opinions and I know not everyone will agree with me. At least you get a forum to disagree with me.
And who knows? Maybe science will shift again in favor of acepromazine in the future (as Megan has noted with respect to seizures post-ace)––or back to shock doses of steroids for that matter. I'm willing to change back, too, if the science supports it.
Dr. Patty Khuly October 23rd, 2009 07:08:15 AM
"evidence-based medicine" includes personal experience, as I'm sure any vet in practice for a decade or more will attest. Excluding the evidence presented by owners is ignoring significant evidence.
Evidence-based medicine actually puts very little weight on personal experience (even one's own or that of experts in the field). As an individual, I bring too many emotions and too spotty of a memory to my experiences to have reliable evidence stored within my head. For example, my first case on Critical Care was a puppy who bled out into her abdomen following a routine cystocentesis. Just because I've never seen another case like that doesn't change the power of that first memory, and the fact that I'm terrified to do cystos now. Is that a fair use of the "evidence" presented by my first case?
The best quality of evidence is the gold standard double-blind-placebo-controlled-clinical-trial-type study, then retrospective or case control studies, then case series studies, then experiences of an individual expert in the field, then one's own experiences. I'm not saying that we don't or that we shouldn't rely on our experience or experiences of owners, but relying on personal experience alone is what leads to the perpetuation of misinformation.
Megan October 23rd, 2009 07:32:24 AM
Brava, Megan, brava!
The future of scince is still bright.
M
Marc October 23rd, 2009 08:35:54 AM
Acepromazine has never been shown to lower the seizure threshold in dogs. In anesthesiology (I graduated vet school in 2008) - they explained that this misconception is related to another phenothiazine that does lower the seizure threshold. This was then linked to acepromazine, and that notion has persisted for years - despite evidence to the contrary. Further, neurologists are now using small doses of acepromazine in actively seizing patients that - for some reason - won't stop seizing with traditional Valium, phenobarbital/pentobarbital, and sometimes propofol. At least - this is true where I graduated and also at the place where I did my small animal internship. I don't hesitate to use it in seizure dogs, although it's not always my first choice.
ER Doc October 23rd, 2009 09:04:31 AM
You're also mixing classes of drugs that don't necessarily fit together. You compare acepromazine with Domitor/Dexdomitor and hydromorphone, but those aren't drugs I necessarily immediately reach for (or were taught to reach for) to help an anxious animal relax (especially in the hospital).
Domitor is profoundly sedating, obviously - but it comes with a whole host of worrisome effects - notable bradycardia and peripheral vasoconstriction are just two. I use it like water in ER, don't get me wrong - but for things like wound care, laceration repair, orthopedic xrays, etc.
In my experience, hydromorphone only has a mild sedative effect - especially when compared with acepromazine. Post-operatively, I often use a combination of those 2 - one for pain (hydro, obviously) and the other to help with post-op anxiety.
Lastly, this bothers me: "Sedating pets without regard for what they may experience is the height of human hubris." As a vet yourself, I have absolutely no doubt that you know how difficult (truly it's impossible, in my opinion) to know what an animal is feeilng. We can guess based on many things - but to truly know is never going to be possible - just like I can't truly know how you see the color blue or how you feel when you get morphine. Even more so in our pateints, because they can't even tell us.
On a sidnote, we are still using thorazine for nausea in our patients. It is one of the most potent anti-emetics I've ever used - including Zofran.
Just my $0.00002 (less than 2 centS)
ER Doc October 23rd, 2009 09:11:49 AM
Don't get me wrong, just because I defend ace doesn't mean I use it exclusively. I use everything and base it on the individual and the procedure: dexmedetomidine, Ket/val, val/propofol, midazolam, morphine, hydro, torb, buprenorphine, locals, regionals, neurolepanalgesia, cri's, etc etc. but I know that acepromazine can be the best choice in some situations. If a client comes in with a preconceived opinion against its use, then I am pressured to avoid it and that can increase the risk for that patient.
"Art" comes into play when we recognize that science does allow us some leeway in most procedures as to what protocols to choose. I would bet my career that you could present one patient having one procedure and get several preferred protocols from any number of board certified anesthesiologists. Personally, I find "kitty magic" to be much heavier handed than opiate/ace, ket/val and I only use it on very aggressive cats. My perference, my art.
Personal experience is very important but I need to know details. I absolutely want to know if your dog has seizured in the past, has exercise intolerance, is on what herbal supplements or drugs but telling me he had trouble under anesthesia or a sibling died under anesthesia does me very little good without drug dosages,etc. Most of the breed related "problems" with drugs or anesthesia isn't backed by documentation. Kate's greyhound may have had a rare hyperthermic reaction that greyhounds can have with agitation. The chinese cresteds were probably hypothermic because they are small dogs with large surface areas. Both of these events are blamed on ace without good evidence that it was the cause. Both of these events can be mitigated (as anna pointed out) when the details are known. That is why the science that megan discussed is important.
virginian October 23rd, 2009 09:12:59 AM
This article relates. It's about medical thinking in general, not about humans specifically.
http://www.incharacter.org/article.php?article=164
Groopman's short bio is at the bottom if you want to check out his credentials ahead of reading the article.
Will October 23rd, 2009 09:30:18 AM
Interesting discussion — one of your best blog posts ever for provoking interesting discussion. As a result, I'm going to revisit my own discussion with my vet about using Ace to sedate my dog on that last trip to the vet. Because, you know, this is what thinking consumers of veterinary services do.
Deanna October 23rd, 2009 10:14:26 AM
"Most of the breed related "problems" with drugs or anesthesia isn't backed by documentation. Kate's greyhound may have had a rare hyperthermic reaction that greyhounds can have with agitation."
If a pet can be so slowed down in its reactions - sort of stuck in molasses - for an indeterminate time under ace (when they look drunk or stoned), but can, at any moment, with various stimulae that causes various agitation (metal clanging, other loud noise, or even touch) , change into severe biting, or racing heart/shivering/body temp rise leading to seizures, then yes, an owner has the right and obligation to remember that and explore its use with other dogs to try and make sure whatever the agitation doesn't occur again. And any vet that dismisses that concern out of hand, because it's just "personal observation" and therefore anecdotal and therefore of absolutely no legimate value, isn't getting my animals to work on.
I understand science and evidence-based medicine very well, thank you, and still weird things happen. I'm not the only person who's had a greyhound die from hyperthermia. How many of them had it start because of agitation while under ace, we don't know. I'm sure it's not all of them, just as I'm sure it's not none. I know it's a weird thing. Why can't medicos (of any stripe) at least be willing to admit that maybe, just maybe, because of the possibility of weird things happening, they should bear in mind, that it could happen again? Unless my dog's bleeding out it front of us, at least give the courtesy of not ignoring me.
KateH October 23rd, 2009 11:04:26 AM
"Evidence-based medicine actually puts very little weight on personal experience (even one's own or that of experts in the field)." That's really too bad if it's true (and I don't think it actually is).
"As an individual, I bring too many emotions and too spotty of a memory to my experiences to have reliable evidence stored within my head. For example, my first case on Critical Care was a puppy who bled out into her abdomen following a routine cystocentesis. Just because I've never seen another case like that doesn't change the power of that first memory, and the fact that I'm terrified to do cystos now. Is that a fair use of the "evidence" presented by my first case?" No, your EMOTIONAL reaction wouldn't be but I was referring to facts, evidence; not emotional reactions.
"The best quality of evidence is the gold standard double-blind-placebo-controlled-clinical-trial-type study, then retrospective or case control studies, then case series studies, then experiences of an individual expert in the field, then one's own experiences." Perhaps, but we all know how very few topics get that much study, don't we :) Would you argue to do nothing until then? Or follow what is becoming clear is outmoded until that level of proof is finally on the table? I hope not.
"relying on personal experience alone is what leads to the perpetuation of misinformation" I never even inferred that! Personal information and pet specific information is, of course, supplemental.
PJBoosinger October 23rd, 2009 11:26:00 AM
Evidence based medicine is fine for public health planning and for treating groups and individuals without a history. Based on good scientific and statistical evidence, the sound of hoofs in the US should indeed bring horses to mind. But not, perhaps, if you're working at Lion Country Safari. Idiosyncratic reactions to most any drug are quite common in humans, I see no reason they wouldn't be in animals.
Will October 23rd, 2009 12:32:43 PM
Personal experience is very important but I need to know details. I absolutely want to know if your dog has seizured in the past, has exercise intolerance, is on what herbal supplements or drugs but telling me he had trouble under anesthesia or a sibling died under anesthesia does me very little good without drug dosages,etc. Most of the breed related "problems" with drugs or anesthesia isn't backed by documentation. Kate's greyhound may have had a rare hyperthermic reaction that greyhounds can have with agitation. The chinese cresteds were probably hypothermic because they are small dogs with large surface areas. Both of these events are blamed on ace without good evidence that it was the cause. Both of these events can be mitigated (as anna pointed out) when the details are known. That is why the science that megan discussed is important.
So, you can identify the "real problem" with Kate's greyhound and with the Chinese Cresteds without any information but what Kate and I have provided, huh? Really?
And it's just a wild coincidence that the Cresteds would have this problem only during the surgeries in which Ace was used, and not in the surgeries--before AND after--in which Ace was not used.
Gotcha. Completely clear now.
Lis October 23rd, 2009 03:51:35 PM
Lis, I didn't identify the real problems. I just questioned whether youhad. I simply stated the possibilities of what happened knowing the properties of the drugs and the breeds involved. Sooo let's examine this question regarding the Chinese Cresteds. Let's make sure we are clear. What other drugs were used with the ace? What dosage of ace was used? What were the preop, intraop, postop temps? Were they on fluids? Was the blood pressure measured? What were the pressures? And what exactly was the "scarey experience"? Did they stop breathing? Did they sleep along time? Did they throw cardiac arrythmias? Unless we have the whole picture, we can't begin to speculate what really was the cause of these problems.
Kate, I am not dismissing your concerns. I know that must have been a frightening experience for you and your dog. I am questioning your assumption about ace being the cause with the information you gave me. Greyhounds can get stress hyperthermia whether they are sedated or not. There are reports of it after any number of protocols some including ace some not. Your dog may have had the exact reaction on another protocol or had a different reaction on a different day to ace. Could it have been a wierd thing and it was the ace that caused it? Sure, but you haven't provided enough information here for us to see that.
The bottom line is that it is entirely possible to have unusual individual reactions to individual drugs. That is why it is very important to keep good records of drugs and dosages and effects for every procedure we do. It is a big jump, though, to say that an individual reaction is a breed-wide reaction to a particular drug without the evidence to prove it. We would be throwing out the baby with the bath water if we stopped using a particular drug without true evidence that it is causing problems.
virginian October 23rd, 2009 04:28:00 PM
Wikipedia's EBM entry says:
Using techniques from science, engineering, and statistics, such as meta-analysis of medical literature, risk-benefit analysis, and randomized controlled trials (RCTs), EBM aims for the ideal that healthcare professionals should make "conscientious, explicit, and judicious use of current best evidence" in their everyday practice. Ex cathedra statements by the "medical expert" are considered to be least valid form of evidence. All "experts" are now expected to reference their pronouncements to scientific studies.
You can see a more thorough list of the levels of evidence here, with the lowest ranked evidence being "Expert opinion without explicit critical appraisal."
I'm not arguing that personal experience is worthless- obviously the personal experience of a clinician who has been practicing for 20 years helps to make him a better clinician than my own short amount of experience as a 4th year vet student. That said, personal experience does lead us astray as practitioners. Being trained in Minnesota, I will always have blasto on my rule-out list when I see a coughing Labrador retrieiver even though rationally I know that if I go to Seattle, there is no blasto there. My own personal experience has shown me that out of the 10 patients I've had that have had cystocentesis performed, one bled out. Not even considering my emotional reaction to the case, my own personal stats would give me the impression that 1 in 10 dogs have a life-threatening complication due to a cysto- which is nowhere near the true complication rate if you look at actual evidence.
While obviously very few topics in vet med make it to the level of being studied in a double-blind placebo-controlled clinical trial, that doesn't mean that we shouldn't strive to eventually reach that level of evidence. When we have no data or no evidence beyond that of a "medical expert", we make do with what we've got.
Megan October 23rd, 2009 04:34:19 PM
OK, all this bandying about of "evidence based medicine," randomized control trials, and the like sounds good enough.
But here is my problem with all of that:
While the rigors and standards of these practices are there to help ensure the conclusions of studies come from "sound science," clinical trials, etc. can only address what they were designed to study. Which leaves an ENTIRE universe out there of issues, treatments, supplements, conditions that never get studied.
Long before anyone ever designs or obtains funding for a scientific study, there is evidence. That is, after all, where many of the "signposts" of what needs to be studied come from.
Much of this evidence is anecdotal. But when dozens and then hundreds and then thousands of people (or animals) have similar experiences, its meaningful, even if no one deigns to study it.
Entities (pet food companies, drug manufacturers, scientests) are very often if not most often, motivated to fund or obtain funding for studies due to the promise of gold at the end of the rainbow. If there ain't money to be made from it, good luck getting someone to fund a study of it. Like treatments for, and characteristics and causes of EXTREMELY rare diseases.
On the other hand, if there is significant money to be made . . . it's another story.
I think a good example of this is studies that reveal that a prescription diets, such as Hills, provide "evidence based clinical nutrition" (quote from their site). They design studies that end up showing - voila, clinical improvements on their food compared to control groups.
My question is this:
What is the control group eating?
And: Where is the clinical study in which clinical outcomes (glycemic control) between pets being fed dry Hills M/D food are compared with those of a control group eating low-carb, grain free wet food such as Wellness?
You won't find such a study.
So, they can go around saying their study found that pets did better on their RX food than on . .. what? Junk?
That doesn't prove this is the best food for diabetic pets, but it "passes" with many vets who don't think for themselves as evidence that they need to be selling RX food to their clients.
On the other hand, there are good examples of things we KNOW from anecdotal evidence, but can't get vets to adopt because no one has paid for a "scientific study of it yet."
Here is an example (diabetes again -- sorry, it's what I know)
The use of Levimir insulin in diabetic cats.
There have been no studies of the use of levimir in diabetic cats. As a result, many vets refuse to prescribe or use it if asked, becuase there are no "studies" showing how it works in cats.
However, there are now hundreds of diabetic cats being managed on levimir and owners who have daily blood glucose charts showing improved control with that insulin.
There is no "evidence based" study to show it.
But it's still true. That's not to say it will be the best insulin choice for every cat (you can't say that about any insulin) but I think it's enough to prove that it is an excellent insulin choice for many cats.
So, I have only so much respect for so called "evidence based medicine." Because the people who use the term generally only accept certain kinds of evidence, and discount others. More importantly, because of the definition of what counts as evidence based, someone with financial motives is typically involved in designing or benefiting from the outcome of the studies, and disinterested in investigating avenues that would likely result in conclusions no one can profit from.
stefani October 23rd, 2009 06:05:41 PM
Stefani: When Hills does a food trial, the control food is a food manufactured by Hills to meet AAFCO specifications. It is essentially a regular Hills adult diet or maintenance diet. I have a friend who represents Hills, and I've been to one of their factories (in Topeka). They explained the process of a food trial. Do I believe everything I hear? Not necessarily - especially when it comes to profit motivated companies. Is it the best we have? Definitely.
Evidence based medicine will trump "personal experience" every time because it helps eliminate confounding factors - such as owner bias, the placebo effect, and many other things that skew anecdotal evidence. Is it perfect? No, but it's the gold standard for a reason.
ER vet October 23rd, 2009 07:23:07 PM
Thank you ER vet for clarifying control groups in Hills studies.
So they prove that one type of Hills food is less bad than the regular kind. OK.
Legions of cats actually became diabetic on a diet of their dry food. Including my own. Ah, but that's only anecdotal, LOL.
Hey, maybe the dry has an ingredient in it that causes diabetes? Wonder if we could get them to study that. NOT.
Stefani October 23rd, 2009 08:05:04 PM
ER Vet, a study where the control group is using the Hills adult maintenance diet, does nothing to establish that the "prescription" diet is better than, or as good as, a genuinely high quality diet, whether from another manufacturer, or home-cooked.
And telling us we're going to kill our pets with home-cooked or raw diets is gonna fly with fewer and fewer people, as more and more of us have pets who are healthier and happier on home-cooked or raw thanthey were on the junk Hills and Iams push as "high quality" pet diets. The fact that there are no major corporations interested in funding the studies to formally assess such diets does not make the real experience of people with their real, live, healthy pets invalid or irrelevant.
Lis October 23rd, 2009 08:07:13 PM
"Hey, maybe the dry has an ingredient in it that causes diabetes? Wonder if we could get them to study that. NOT."
Or maybe they have studied it and shown that it might not:
"The energy percentage of dry food in the diet was not significantly correlated with the development of diabetes mellitus (P=0.29), whereas both indoor confinement (P=0.002) and low physical activity (P=0.004) were. The results indicated that the proportion of dry food in a cat's diet may not be an independent risk factor for the development of type 2 diabetes mellitus, whereas physical inactivity and indoor confinement are."
Indoor confinement and physical inactivity rather than the proportion of dry food are risk factors in the development of feline type 2 diabetes mellitus.Vet J. February 2009;179(2):247-53.
L I Slingerland1, V V Fazilova, E A Plantinga, H S Kooistra, H S Kooistra, A C Beynen
virginian October 23rd, 2009 09:32:55 PM
Lis:
"ER Vet, a study where the control group is using the Hills adult maintenance diet, does nothing to establish that the "prescription" diet is better than, or as good as, a genuinely high quality diet, whether from another manufacturer, or home-cooked."
Well, obviously. I made no statement to claim it did. Stefani asked what Hills compared to, and I was telling her.
I've never told a pet owner that they would kill their pet with raw or homecooked diets. I HAVE seen a lot of pets with hemorrhagic diarrhea and severe Salmonella/clostridrium-like illnesses fed those diets - but that's just ANECDOTAL evidence, so I don't necessariy ascribe it to simply home-cooked and/or raw foods. I understand the difference between anecdotal and evidence based medicine. I've seen plenty of dogs on commercial diets with the same type of illnesses.
Just because people perceive that their pets are happier and healthier on raw/home-cooked diets doesn't make it true. There's a name for that particular kind of bias - having a core belief (commercial diets are bad) and looking for evidence to support that assumption while ignoring evidence to the contrary- I think it's called selective or selection bias or something - and it's part of the reason that evidence based medicine is so important.
My caveat: I have no problem with people trying home-cooked meals or raw diet. Every individual pet is different. I have never counseled someone against feeding this kind of diet, although I do have SOME reservations about SOME of the raw diets I've been told about by owners -especially when their dog is laid out flat with blood pouring out of its rectum after being fed raw chicken - as happens to people with Salmonella.
ER Vet October 23rd, 2009 11:03:04 PM
PS: This thread has been hijacked again. Wasn't the original discussion about acepromazine vs other sedation?
Er VET October 23rd, 2009 11:07:33 PM
"Kate, I am not dismissing your concerns. I know that must have been a frightening experience for you and your dog."
Yes, it was a bit more than just frightening - he died.
And, true, I don't know every dosage detail in his case, because the vet wouldn't tell me what dosages he'd given. I'd told him that greyhounds have - anecdotally - occasional problems with deeper sedation because of their smaller percentage of body fat compared to other dogs of the same weight. He laughed. I had worked for this man for more than a year, and he'd never treated a greyhound, but no other dogs had had anesthesia problems, so I went on to my own dental procedure, leaving the dog I'd waited for more than 20 years to have, to his dental. Less than 8 hours later my dog was dead. Yes, there were issues about the whole day that I don't have accurate information on, but I do know that the same vet has worked on multiple greyhounds since then and a number of them have had bad reactions, so although I ALMOST would have thought my dog's reaction was "just" a fluke, it's been shown, at least to my satisfaction, that greyhounds can have weird reactions that out to be taken into consideration - not laughed at.
KateH October 24th, 2009 12:26:55 AM
That should be " 'ought' to be taken into consideration"
KateH October 24th, 2009 12:28:54 AM
Wow! So many responses (that I've only skimmed). It's amazing how many responses and opinions people have on sedatives and pain relief. I hope they are mostly saftey related.
Our dentist even defaults to "ace" when speaking about sedating "her dog." Scary. The comment regarding Ketamine "...I've know people who have tried it..." is disturbing. (And why we drugtest at our hospital).
Stay cautious,
Robert October 24th, 2009 11:00:16 AM
My year old staffie was prescribed ACP as a general sedative to stop her jumping about after an op for luxating patella last year. It had horrendous effects on her. Firstly she lost control of her bowels, so I was following her around cleaning up after her. This alone upset her. But she hated the feeling. She kept backing into corners and tried to chew her puppy gate (and my clothes airer), and then tried to chew the glass inthe patio doors. The poor little soul was so distressed. I can't describe how upsetting it was. In the end I videod her for her vet who didn't believe me and kept insisting I increase the dose.
We've now changed vets. If my dogs have to have an anaesthetic I insist that they are not given ACP as a pre-med. I wouldn't do that to them.
Julia Livesey October 24th, 2009 01:29:01 PM
BevBC: I have a few groomer friends that have used Benedryl (with owners consent) effectively & without heavy sedation. Maybe ask your vets about that? Personally, I would rather muzzle a dog & have two people ---I'm thinking the dreaded toenail clip--then resort to a drug.
I have had two different dogs react dysphoria to Torbutrol. I have had one react aggressively to any sort of pre-anesthetic/ tranquilizer-- T/X/T
Megan: I have one dog that bleeds every single time after a cysto , for several times during urination (usually one day-post), my friend with the same breed does too. I really wish there was a better method to obtain a sterile sample, since it is disconcerting to see. I don't think your 'fear' is unfounded, and perhaps will always remain a last resort.
On a humerous note: Years ago, my Zoe's vet expressed serious concern about her coming around post-spay. Apparently, she remained motionless on her back with all 4 legs/feet up. She told me she has never seen anything like it and she looked like a "beetle bug" . She handed her to me feet up & I slowly tipped her over to the ground, so she could proceed to do an overlong pee. Since obtaining her records, I recall that it was Emily, the newbie, at the time, that did both her C-section & spay--and a great job on both!
Barbara A./NH October 24th, 2009 05:26:10 PM
I don't like ace....but I dislike ketamin more, and I never allow my cats to be given ketamine. I've seen too many bad cat rxns...
I had to give my dog ace to get him to the vet to be euthanized about 6 years ago. He was senile and terribly aggressive at the end. The ace really was not effective with the aggression, it just made him wobbly and slower. IT made a horrific experience worse.
LorriM October 24th, 2009 06:55:07 PM
ER Vet: Just wanted to address this one line:
"Lastly, this bothers me: 'Sedating pets without regard for what they may experience is the height of human hubris.' As a vet yourself, I have absolutely no doubt that you know how difficult (truly it's impossible, in my opinion) to know what an animal is feeilng. We can guess based on many things - but to truly know is never going to be possible - just like I can't truly know how you see the color blue or how you feel when you get morphine. Even more so in our pateints, because they can't even tell us."
Yes, that's true. That's why pain relief was so slow in coming to the vet profession. That's why my broken arm back when I was 11 years old meant Tylenol––no opiates whatsoever. That's why infants who did not receive pain relief for open heart surgery died at more than twice the rate than those that did (back in the 70s).
It's up to us to push the envelope of what's acceptable based on what we do know. We strongly suspect phenothiazines allow animals to maintain awareness. We know that most (in sedating/tranquilizing doses) cause profound dysphoria in humans. And we have alternatives.
In a previous comment I mentioned drug combinations I now use in my hospital which have supplanted some of my heavier ace protocols. Dexdomitor microdoses with hydro now replaces all my previous aggressive dog protocols. No, it's not for sedation. It's for "stopping" them, which is how ace is too often employed when safer (reversible!) alternatives like this one are available.
As for home settings and travel, alprazolam (laced with perhaps a bit of diphenhydramine) is excellent. For storm phobia, fluoxetine provides and excellent base and works synergistically with alprazolam or diazepam. The sedating dose of alprazolam may be higher than what you might think necessary, but once you get past this obstacle, you'll find it works.
We need to try new combinations of drugs (based on our anesthesiologist's protocols, of course) if we're to get beyond the heavy use of any one drug.
Back to your original point, There's plenty good reason to suspect that ace is not the safest, most humane drug for the sedating/stopping purposes we put it to. Why not try alternatives?
Dr. Patty Khuly October 25th, 2009 07:09:01 AM
Dr. K:"Yes, that's true. That's why pain relief was so slow in coming to the vet profession. That's why my broken arm back when I was 11 years old meant Tylenol––no opiates whatsoever. That's why infants who did not receive pain relief for open heart surgery died at more than twice the rate than those that did (back in the 70s)."
hear, hear, I am so glad you posted that! I do remember the 70's very well and the thoughts of immature nervous systems (both human and animal) thought to prevent full "pain expression". How on earth were we all that ignorant?
And fixing broken bones, invasive surgeries, s/n, without nary a concern. Still that is unrecognized in many practices, whether fear of 'human abuse' or wanting the animal to remain motionless and quiet, because coping with pain aids that!
We evolve with better & safer protocols every year, it only makes sense to update.
Barbara A./NH October 25th, 2009 11:19:11 AM
Of course it is wonderful that we have realized that animals suffer from post-op pain. You can't assume that drugs work in the same way in animals as they do in humans, though. There are differences between animals and humans and even cats and dogs that make this true. Morphine is metabolized differently in animals and even differently in dogs than it is in cats. We believe that etomidate suppresses cortisol for much longer periods in humans than it does in dogs or cats etc etc. It is very hard to say how a sedating drug is perceived from an animal's point of view.
I think some of your other statements also need qualifying:
"We strongly suspect phenothiazines allow animals to maintain awareness."
Yes, they do. All of our sedating drugs do.
"We know that most <phenothiazines>(in sedating/tranquilizing doses) cause profound dysphoria in humans. And we have alternatives."
Dysphoria can result from any of the drugs we use for sedation. It is most commonly associated with opiates and benzodiazepines. Acepromazine is often added to pre-ops to PREVENT dysphoria.
"Dexdomitor microdoses with hydro now replaces all my previous aggressive dog protocols. No, it's not for sedation. It's for "stopping" them, which is how ace is too often employed when safer (reversible!) alternatives like this one are available"
I do too (except that I find butorphanol works better than hydro) but it isn't because dexdom is "safer" it is because acepromazine doesn't work well in that situation. Reversibility does not make a drug safe. Dexdomitor can cause dramatic hemodynamic and neurohormonal changes. In some situations, dexdomitor would be overkill or is contraindicated in a particular patient. Ace could be tthe perfect addition to the sedative protocol or preop in that instance.
"to get beyond the heavy use of any one drug."
Well, yes, that's true of all our drugs. We should have available a wide variety so that we can tailor protocols to the individual and the situation.
We are still talking about some very different situations here. At-home tranquilization for behavioral reasons, sedation for restraint or short procedures. pre-ops meant to be followed by induction and maintenance of anesthesia, and tranquilization during recovery. Drug choice is going to vary greatly between these different situations. Dexdomitor, benzodiazepines, and acepromazine all have their place when given at appropriate dosages and with proper patient selection. No one of these drugs is right for all situations nor are they contraindicated in all situations.
virginian October 25th, 2009 12:46:37 PM
Virginian: You know, I think we're on the same page. The only thing I'll continue to disagree with you on is the issue of tranquilization vs. sedation. The definition of tranquilization according to my vet anesth textbook claims the primary difference between these two classes of drugs lies primarily in the degree of awareness experienced. For true sedatives, there ensues an apathetic lack of clarity, whereas for tranquilizers the body may be quieted via the body but the awareness and physical/psychological sensitivity may remain.
I don't pretend to know what my patients experience, but I will argue that large doses of acepromazine 1-2 mg per kg (!), as cited in Plumb's, are more likely to induce the kind of chlorpromazine-like dysphoric reactions that are likely unnecessary in light of other drug choices.
The small doses of ace you're talking about as pre-meds and sedation cocktails are not what this post is truly about. Wielding ace as a naked sedative to whack the s--- out of a raging or inconvenient animal is the issue. I, for one, would like to see it used as a last resort in these cases. But mostly, I'd just like to see clinicians be more thoughtful about their drug choices.
And I can see you don't suffer from that problem. After all, when was the last time you offered ace at Plumb's sedation dose?
Dr. Patty Khuly October 25th, 2009 06:34:32 PM
To tell you the truth, I don't consult Plumb's for any of my anesthesia or sedation dosages. I think there are more up to date resources. My normal dosage for acepromazine is 0.005mg/kg, a fraction of Plumb's.
I agree with you that it is a rare case that would need a high dose of acepromazine alone (I never say never, though) but I feel the same about dexdomitor.
I think there is a very grey area between tranquilization and sedation depending on how an individual reacts to a certain dose. Even when they are seemingly unaware with eyes rotated and body prostrate, it only takes a noise or a change in position for them to be looking around and even biting.
I, too, would like clinicians to be more thoughtful of their drug choices but I also want pet owners to know that there are very real and important reasons why we pick the drugs we do and it may not agree with something they read on the web.
virginian October 25th, 2009 08:21:12 PM
Patty:
That's where I disagree: I haven't seen anything to prove to me that acepromazine isn't safe or humane. I have an enormous amount of success using it. In fact, I feel like it's a lot safer that Domitor (which I also use on a daily basis, but - as I mentioned above - for different purposes).
I love opiates. I dispense them like candy in the ER. They are cardiovascularly safe and excellent for pain control. They aren't (with the exception of Torb - which SUCKS for pain control) that great at sedating my patients.
I think acepromazine is a good sedative choice for a lot of situations - post-operatively notably.
Does that mean that I won't try other protocols? Absolutely not. I love to learn safer, better ways to keep my patients comfortable and stress-free. Xanax is something I have little experience with in my patients because it takes a while to reach an effective therapeutic level and doesn't have much use for me in the ER setting.
I still think that acepromazine is a good drug with a lot of important uses, and I think you are giving it a bad rap here and scaring off people from it unnecessarily. I graduated vet school 2 years ago, and the anesthesiologists are definitely still using it in academia. As I said before, even the neurologists are using it.
ER Vet October 25th, 2009 08:26:35 PM
I graduated vet school 2 years ago, and the anesthesiologists are definitely still using it in academia.
Yup, we use ace regularly at the U of MN as well. I just finished my anesthesia rotation, where we were encouraged to experiment with protocols (with anesthesiologist supervision, of course), and I settled on ace/glycopyrrolate/midazolam as my favorite premed combo. That said, our anesthesiologist agreed that Plumb's dose for ace is way too high, and we dosed it at .005mg/kg (or .0025 mg/kg in older, quieter animals).
Megan October 25th, 2009 08:54:48 PM
Megan: Exactly. In small doses as a preanesthetic and to potentiate other sedatives or as an antiemetic. Not for whopping sedation as you'll find it is most commonly applied in general practice.
Dr. Patty Khuly October 26th, 2009 09:56:46 AM
ER Vet: When does an owner get a chance to make an informed decision about the use of acepromazine? When it's administered for noise phobia, behavior problems or travel. Not as part of a pre- or post-anesthetic protocol (where I employ it, too, as I've written).
This is where I disagree that ace is best. Not at the doses I see commonly used in private practice. (Plumb's, primarily.)
I believe owners need to be exposed to these issues so they can make up their minds about them.
It may be the first time you've been exposed to the welfare angle with respect to ace but I promise you that plenty of behaviorists are talking about this. Especially with respect to noise phobia, for which it's handed out like candy in my storm-riddled part of the world.
Dr. Patty Khuly October 26th, 2009 10:06:40 AM
Dr. K., your storm-riddled part of the world isn't the only place it's handed out like candy. Animal behavior modification using anything other than ace, including training, is almost a foreign concept to most (GP) vets in Ohio. Your dog hates coming to the vet - here's some ace for before you get here. Your dog doesn't handle thunder and lightening - here's some ace for the spring. Your dog is afraid of fireworks - here's some ace to use during the summer. I even know a vet who prescribed ace for the holidays because the stress caused by lots of people visiting. Of course, the dog was PTS after it bit someone who poked their finger in the crate because they thought the dog was dead, but hey, who would've thought maybe a different approach would have made more sense? That same vet continued, the following spring, to give out ace for the family's new puppy for its thunderstorm issues, so obviously, expanded thinking about the best way to deal with behavior wasn't happening with that vet.
KateH October 26th, 2009 11:27:40 AM
Thank you for clarifying. I'm most concerned about people who are posting responses about not letting their vets use acepromazine at all in their pets - as in a pre or post-operative period. I just didn't think the article was clear on the point that acepromazine still has a place in veterinary medicine - an important place. I re-read the post and I do think that you make it clear that ace has an important place in anesthesia, however I am afraid that point gets lost by the end of the article.
All that said, I pretty much agree with everything you said about acepromazine for at home sedatio (although I use it in great success in my cats when we travel).
As a sidenote, many veterinarians have told me that they don't like Plumb's - but short of using Papich - which is kind of the anti-Plumb in its brevity - what other good reference is out there?
ER Vet October 26th, 2009 03:06:53 PM
ER vet, most of my resources are online. I like VSAG for anesthesia and sedation info and there is always VIN. I would also encourage your support staff to register on VSPN. It is an invaluable resource.
virginian October 26th, 2009 04:11:13 PM
virginian: I also get to VSAG and VIN. I fear Plumb's but use it as a starting point almost always when I'm new to the drug. So convenient on VIN, you know.
VIN discussions are great but always incomplete. I tend to supplement by calling around to my local internists when in doubt. They always have their ear to the ground on most meds.
Buying your local specialists lunch every once in a while gets you great access, btw. Worth every penny.
Dr. Patty Khuly October 26th, 2009 07:19:38 PM
I'll also surf the proceedings in the library at VIN, if only to see how much the specialists differ on a given subject but lunch is always nice.
virginian October 26th, 2009 07:39:15 PM
I do love VIN, but Patty is right - the information is often incomplete - generally in the msg boards.
Patty: I also use Plumb's as a starting point and modify my doses according to experience. For instance, Domitor is listed to give at a WHOPPING 40mcg/kg for sedation/anesthesia. I find that I can do minor wound cares on 5mcg/kg (mixed with butorphanol and with local lidocaine) almost all of the time. The thought of giving a dog 40mcg/kg of Domitr gives me the screaming horrors. The MOST I have ever given was 10mcg/kg - and that was in a dog that weighed 120lbs, was aggressive, and sent my tech to the hospital. I also agree with you on the acepromazine ranges. I start much lower. I also dilute my acepromazine to 1mg/mL instead of 10mg/mL so that it's more user friendly for small dogs.
Overall, I think Plumb's is a GREAT, very thorough reference for information on drug interactions, pharmacology, toxicity/overdosage, and that sort of thing. The doses it gives - depending on the drug - can be a little iffy, so I generally check VIN or other references if it's a drug I'm not familiar with and comfortable using.
In the case of using medications - anecdotal evidence IS priceless. It's not a book that tells me how a patient responds to a certain medication. It's watching them and seeing for myself.
ER Doc October 27th, 2009 08:03:16 AM
And I remember being given no sedation at all for dental procedures in the 70s, 2 nurses holding me down while I screamed bloody murder and tried to bite and scratch my way free!
"We've never had a patient react like this before" says the one nurse to the dentist. "Should we give her something for the pain?"
"Kids don't feel dental pain," the dentist said.
Oh yeah?!
Hear hear that the times have changed!
BCBev October 28th, 2009 08:34:36 PM
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