Senior dog restless, crying after mirtazapine. Is it serotonin syndrome?

Mirtazipine is typically well tolerated in dogs. You may see sedation or drowsiness. Symptoms that should be addressed by your vet include low blood pressure or increased heart rate. Given his age, you may want to have him checked out at the nearest veterinary ER or put a call in to the Pet Poison Helpline ( (855) 764-7661 ). There is a fee for this call, but they will have toxicologists and doctors who can tell you definitively if Cody is at any risk.

Serotonin syndrome is certainly possible with fluoxetine and trazodone together, or even just fluoxetine by itself, but what you're seeing with Luna does not sound like serotonin syndrome. With serotonin syndrome there's just too much of everything, too much energy, too much vomiting, too much diarrhea, too much muscle movement (tremors and seizures), too much pupil size. Sedation is an expected and desirable side effect of Trazodone, so in this situation I wouldn't worry. I would recommend giving a slightly smaller dose of trazodone tomorrow to see if that is enough to keep Luna calm. And always, if you're worrying about it and not sure, take Luna to an emergency clinic for an quick check in. Also, these two drugs are used together VERY commonly in veterinary medicine, but I don't think human doctors use them together, so you'll see lots of precautions against it while reading online. I hope that helps you feel better! Thanks for using Petco Pet Education Center, formerly Petcoach.

Hi there. I would be concerned with Hershey developing serotonin syndrome with concurrent use of trazadone and fluoxetine especially if you are giving them together often. It has to do with how the drugs are metabolized in the body and what receptors they work on. Side effects can be as you have listed, as with diarrhea, labored fast breathing, etc. I would try calling your doctor to discuss changing the dosages or weaning off the trazadone altogether. Hope this helps!

Mirtazapine does have a side effect of drowsiness or sedation in pets. It is commonly used in cats as an appetite stimulant. 30mg would be 4 times higher than I normally use, and this overdosage can cause: 57% vocalizing, 38% agitated, 23% vomiting, 21% tachycardic, 15% ataxic and 11% lethargic. The symptoms can last a little longer than 72 hours. As long as Dolly is still eating and drinking normally, I would continue to watch her. If the she is still not completely normal in a day or two, she may need a checkup with a vet.

This could be canine cognitive dysfunction, which is like Alzheimer's in humans. I would have Mitch seen by a vet for this to see if he does have this. If he does, therapeutic foods, exercise during the day, and potentially a drug called Anipryl.

The dosing does go up to 1mg/kg every 12 hours. So Angel's dose at this would be 20mg twice daily, so she should be absolutely fine. I hope this helps! Please let me know if you have any further questions or concerns and I would be more than happy to help you further.

Mirtazipine can cause serotonin syndrome which is characterized by hyperactivity, muscle tremors, vocalization and behavior changes. This is more likely at high doses but has been reported to occur at typical doses as well. It is cleared through the kidneys so a dose reduction is typically recommended for cats with decreased kidney function. Megacolon should not be a concern.