Has anyone had experiences with an adverse reaction to Trazodone?

[horses25]

So my horse is on stall rest for a fractured coffin bone - he is generally quiet but can be the explosive type. Doesn’t weave/pace etc. Anyway…

So the hospital sent me home with him on 15 pills of 100mg 2x a day. We upped it to 16 2x a day after a few weeks (probably didn’t do much) but after he danced around when there was a commotion outside.

So Monday evening, he had spooked at a similar commotion outside, so we decide to give him two extra before his regular evening dose. The next day, after his morning dose, he is completely neurotic but STARING outside of his window - with nervous poops. Nervous poops when the vet’s car pulls up which is unlike him. He was neurotically staring all day long, and wouldn’t eat hay or do anything but stare unless I came in the stall.

He became more “normal” during the evening when it was dark. He was fine overnight. We stopped the trazodone and this has not happened since. I think we gave him too much and he had an adverse reaction. Now I’m afraid to give it at all, I’ve had one vet tell me give him 6 pills once a day, and one telling me to not give it at all if he is fine.

[TWH_Girl]

Geez that sounds awful. Fractured coffin bone, stall rest, oodles of pills to try keep horse calm and then weird reaction and nervous poops. That’s a lot of stress for you too! Lots of other sedatives to try if you’re not comfortable how he’s doing on this one. I haven’t used it on a horse but tried it once for sleep and could not function the next day.

[Bonnie2]

Not a horse, but my dog became neurotic on Trazadone prescribed after surgery.

[fordtraktor]

Don’t worry about overdosing. My mare was on 56 150mg pills per day, you were giving WELL under max dose.

[horses25]

The hospital vet said my horses max dose per day was 23 twice a day. Now that I had that weird incident, I just don’t see how that’s possible.

My regular vet said 16 x2 a day seemed high to him and to try 6. Now I’m just worried about weird reactions like that.

[Simkie]

Yeah, I had one. It really looked like serotonin syndrome, although I couldn’t find anything in the literature describing it in equines. She was spinning in her stall, wild, high temp, loose stool. I very quickly titrated her down and discontinued, and she quickly improved. It was very scary, though!

We put her back on trazodone later, at a very small dose, with no issues.

[Feathered_Feet]

Trazodone is remarkably safe at high doses. However, if not “compatible” with your horse, it probably won’t take a high dose to see that. Unexpected and undesirable reactions to sedatives are not uncommon. I would just try something else, and you could maybe revisit it later just to confirm that your horse does, indeed, have an undesirable reaction to traz.

For what it’s worth, I’ve given it several times to one of my rescue dogs to help with nail trims and I’m pretty sure it makes him worse than just being sober (and I have not had such reactions from other dogs). So you’re probably not imagining it.

That being said, I take it at night for sleep and it does, indeed, put me to sleep

[horses25]

Thank you, what was your horses’dose? How long did you wait to put her back on and at one dose per day?

[horses25]

He was fine until we gave him too much, I think. Or what was “too much” for him

[Feathered_Feet]

Sounds like it was too much for him, then.

Lots of horses do fine on doses as high as 25 (100 mg) tablets/twice daily (or more sometimes!). So I would just listen to the horse in front of you and either drop it down to where it’s having the reaction you want, or try something else altogether, if a sedative is needed at all.

[horses25]

Yeah, he is being pretty good in the stall but can have occasional blips due to outside stimulus. I’d like to give him a lower dose for peace of mind for sure.

[Simkie]

@horses25

Thank you, what was your horses’dose? How long did you wait to put her back on and at one dose per day?

It’s been a few years. I honestly just don’t recall. It would’ve been several weeks, 3-4 ish, before we tried again, and we kept the dose very low.

[hallie2]

I’m a retired psychopharmacologist. Horses have polymorphisms in P450 enzymes, just like humans. these are the liver enzymes which metabolize drugs. This would mean that while the average horse tolerates a certain dose of trazodone, a number of horses will not be able to adequately metabolize the drug and will have marked side effects. Some horses are rapid metablolizers and can’t get adequate drug levels. serotonin syndrome in humans is unlikely except w several serotoneric drugs on board, don’t know about horses; in humans there is almost always a tremor. I have been humbled, in human medicine, by the unexpected and sometimes dangerous adverse effects of drugs at usual doses. In humans, we can test for p450 enzymes, run drug levels and can safely prescribe. You are guessing w horses. Any drug can do anything, adverse effect wise, and, although rare they are unpredictable. I, personally, would never give trazodone to my horses.

[hallie2]

found this.https://www.intechopen.com/chapters/61898

[Simkie]

@hallie2

found this.https://www.intechopen.com/chapters/61898

That’s very interesting. I don’t see any discussion of serotonin syndrome in the equine. Am I missing it?

[horses25]

Do you remember the amount?

[Simkie]

@horses25

Do you remember the amount?

Do you see my response to this question above?

[hallie2]

no but I thought it was good explanation of what might happen if there were a serotonin event. I skimmed but didn’t it say serotonin syndrome uncommon in horses, relative to dogs? or it saw that somewhere else. I did skim the literature and it seems studies of drug metabolism in horses is in its infancy. I find drug metabolism fascinating but almost no one else does.

[horses25]

Did you mean 3-4 weeks or pills?

[fourfillies]

My Corgi went nuts on Trazadone too. I didn’t believe it and rechallenged him. Definitely the Trazadone