My cat stopped Mirtazipine. Why is he sleepy and not eating now?

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.

I would not give her morphine without seeing a vet as this can cause major respiratory depression and severe nausea. Also without seeing if she is healthy for morphine, it could make her get worse. The mirtazapine can be given for an appetite stimulant but cats can only tolerate 3.75mg (1/4 tablet of a 15mg mirtazapine) every 72 hours. If at all possible, I would strongly consider having a vet take a look at her to see if there is anything else they can do for her and to figure out why she isn't feeling well. I hope this helps.

I am guessing the injection given was Cerenia. Side effects are uncommon with the use of this medication, but the most commonly noted side effects were: drooling, drowsiness, diarrhea, and appetite loss. I would be worried and I think he needs to get back to the vet. Were any x-rays or blood testing done? If not, that needs to be done to figure out what is going on. This sounds like it could be something more serious going on. If it was just a simple upset stomach he should be feeling MUCH better after that injection and not sleeping for 10 hours. I would be worried.

He may not feel like eating just yet as it is common it can take a day for his appetite to come back. I would let him rest today and let the medication start working. Try his food or even a little tuna in the morning. If he is still uninterested then you might want to get him rechecked for further testing

Lethargy can be a side effect of an anti-nausea injection such as Cerenia, so that could be why Sunshine is just sleeping. I would monitor her for now, and see if she will eat when she wakes up. You can try to tempt her to eat by offering her some boiled white meat chicken (no bones). If she is still refusing to eat in the morning, I would bring her back into the vet.

Poor girl. Cats typically recover from sedation within 12-24 hrs. Also they generally will still want to eat, even if its just a little bit. Try offering her some canned cat food or canned tuna to try an entice her to eat. If she got fluids yesterday, then she likely isn't thirsty yet. If she isn't herself by tomorrow, then its best to have her re-examined by your vet or get a second opinion. Her thyroid condition alone should not cause her to be quite this ill, so there may be something else going on here. I do hope that Meg is able to return to normal soon! Best wishes and take care.

Thanks for the question. It sounds like Gregory has finished 2 days of the medication that was prescribed by your veterinarian. I would recommend finishing the prescribed medication, and then going back in for a recheck if he isn't improving. At any time if Gregory is getting worse, then don't wait to finish the medication. Often, without more testing (lab tests and x-rays) we don't know exactly what we are treating for. If Gregory is not improving, your veterinarian may recommend more testing to try and find a cause for his symptoms. I'm glad he is doing a little better so far, and I hope his appetite improves.