freaked out piggie

Question
My 6 year old guinea pig, Oreo, is being treated for an inner ear and sinus infection. He is on chloramphenicol, benebac, and metacam. Last night I handfed him as usual shortly before 3 am and when I put him back in his cage, he completely freaked out. He jumped around in his cage as if he was chased by a predator. Even when I took him out he still tried to get away from me, sniffing the air constantly. He quieted down a bit after 4 am. At 8 am I fed him again but he is still extremely jumpy and tries to run away. This used to be the most loving, cuddly guinea pig on this planet. Any idea what is happening? My vet won't be in till next Monday and I am very very worried!
Thanks for your help!

Answer
Chloramphenicol is an antibiotic that's not used by many vets, however it does cover a broad range of infections. The Metacam is an NSAID (non-steroidal anti inflammatory drug) and was given to Oreo to help reduce the swelling caused by the inner ear and sinus infection.  Benebac is a probiotic used to help prevent some of the bad side effects of the Chloramphenicol which can cause problems with the normal flora or bacteria in the stomach.  The Benebac will help prevent that.

It's possible that he's just reacting to the medications, not that he's having a bad reaction, he just may be jittery because of the medicines. I don't think it's anything that's going to harm him and he will probably return to normal once he's through with the treatment.