The vet decided to try Rosie on mirtazapine, an appetite stimulant. I gave Rosie her first dose about five hours ago. About an hour after getting it she became very alert and sought out some food. She lapped at it pretty well for a bit, and then backed away and smacked her lips more dramatically than I've ever seen. This time it was more than just a couple of lip licks, it involved her salivating far more than normal and throwing her head around and essentially biting and chewing at the air. It almost looked as if she was trying to get something out of her teeth. As the evening has progressed I can definitely tell that the mirtazapine is having an appetite stimulating effect for Rosie, and that itself excites me. However, each time she's finished lapping up food she smacks very excessively and sometimes even spins in a few circles before finally settling back down for a nap.
That being said, I have learned that mirtazapine can potentially cause side effects such as agitation. It can also cause drowsiness as well as lack of coordination and stumbling. Since giving Rosie this drug I believe I have seen potential signs of all of these side effects. I will certainly be keeping a close eye on Rosie, as these side effects could potentially lead to dangerous effects. If I become too concerned by what I'm seeing I'll contact Rosie's vet. From what I've learned they should, if need be, be able to give her an antidote drug to reverse unwanted side effects of the mirtazapine.
I also wonder, though, if I should really put all the blame for Rosie's current condition on the mirtazapine. Honestly, I've reached a point where I'm just stumped. Rosie obviously had (and perhaps still has) pancreatitis, given her initial symptoms last week as well as her bloodwork. But now, especially after seeing her sudden excessive salivation and smacking, it's as if she's suddenly also bothered by her teeth, which are not a new issue for her by any means (her age and other health issues had just previously caused any dental work to be put off). One new thought I've had came to me when I remembered a case from when I used to work at a cat clinic -- in this particular case, a cat presented with pancreatitis and concurrent severe dental disease. The vet at that clinic ultimately thought that perhaps the dental disease -- which included a severe infection of one of the canine teeth -- led to the manifestation of pancreatitis. Rosie's vet has not seen any obvious, outward signs that Rosie's dental disease involves any infected teeth, but now I wonder if there is a link between her dental disease and this bout of pancreatitis.
So, that's where we stand for tonight. Rosie is certainly showing more willingness to eat since receiving the appetite stimulant. But, whether or not it is a side effect of the drug or a sudden side effect of her dental disease, she also seems more agitated, especially after eating. Pretty much, I think both I and Rosie's vet wish she could tell us what's wrong and where it hurts. But she can't, so I will keep doing everything in my power to get to the bottom of this with my sweet old girl.