Urgent

My cat Boo was prescribed Cerenia this afternoon - it's been a long month full of syringe feeding and medications trying to figure out what's wrong with her. I was instructed to give her 1/4 of the 16mg tablet every day. I don't know what I was thinking but while feeding I accidentally gave her the entire pill.
I'm sick with worry, I can't believe I did this. I called the emergency vet and they looked up the toxicity levels and told me Boo should be fine. I asked numerous times if there's any side effects to be looking for - they didn't give me any. After doing some research on the medication I see there are possible side effects (seizures, diarrhea). I don't know what to do. The emergency vet is quite reliable here, but I'm still so worried. Any opinions?

Symptoms to watch for:  drooling, lethargy, diarrhea (and or blood in stool), anorexia, and heavy sleeping - conversely, this can also act as an antihistamine-like drug, which could also cause excitability or restlessness or shaking, the latter of which I'd get her to emergency.

If you are still concerned, or if she has any of the above within a few hours, you could take her in and the vet could hospitalize her overnight on IV fluids.

She seems to be alright. I was up with her all night, I haven't seen anything really out of the norm. I ended up calling another emergency vet last night just to be sure. I feel so stupid.

In the future, score all tablet medications before you give them (directly when you get home from the vet or pharmacy) - you can get a pill splitter from any drug store.  This makes it simpler when you're dealing with so many other meds, issues, etc.

Glad to hear she's doing ok, watch her closely for another 24 hours and don't give any cerenia today at all unless the vet directed you to do so.