I Accidently Dropped Some Of My Pills. A Gabapentin Capsule,
ideally, you should make all of them vomit at the earliest...
Detailed Answer:
Hello and Welcome to 'Ask A Doctor' service...
I've gone through your query in details...
I can understand your concerns...
Yes, since this is an uncertain situation, ideally you should make all three of them vomit right away. Afterwards, do observe how they stay. Also, try to feed them something sweet (as some of the metformin may have already been absorbed inside in some of them)...
In case unable to induce vomiting, observing any lack of activities, lethargy, irritability in any of them, I'd request you not to take any chance, take them to the nearest VET-clinic for a prompt check-up without any further delay...
Let me know if I can assist you further...
Take Care
Kind Regards