Can meds cause behaviour changes?

Zorro was on prednisone for a little over a month. His last day was last friday morning, then that night he has put on clavamox for ten days for an infection. A few days ago, he started acting very weird. He usually gives 'love bites' on your nose when your holding him, but now he's started biting everything in his path. He bit my leg two days ago (which really hurt because his one canine managed to find my leg. ouch!) I picked him up and said 'NO! Bad kitty' He usually listens and stops, but this time be freaked out and started clawing, scratching and biting. He's never done anything like this before. He settles down after a bit, but he has been having 'freak moments'.
Do you think he's upset about having to take pills for so long or could the meds be causing a personality change? He gets them morning and evening. It doesn't seem to upset him at all when I give them to him. He usually comes running because he knows he gets treats afterwards.
I'm just a little worried because he's never acted like this before.

Could he be feeling better and over acting out? Or does it really seem like he is not himself when it happens?

I guess it could just be because he's feeling much better. He does have spaz attacks and go crazy zipping around the room, and flinging himself around. Right now he's making funny noises and running a marathon around the bedroom.
I was just a little concerned about the biting since he's never been like that before.
Do you think its just because he has so much energy now and sometimes he just doesn't know what to do with it all and gets aggressive?

Yeah, it sounds like he feeling much better and very happy about it! Some cats do get a bit aggressive when they are all hyped up, just keep playing with him and encouraging his new found health! A simple no or time out when he gets carried away should do the trick! I actually play with Maia with my hand under a blanket so she can get her funky spazzes out! She is so funny, she grabs my hand through the blanket, kicks out with her hind feet, sometimes growls and spits, and takes a big mouth full of blanket!

My Wellington takes prednizone for asthma. I don't know if it is that, or if it would have happened anyway, but he is a much more 'male' cat since he has been on it, and sometimes you would hardly know he is fixed. He 'humps' things, my legs, a cushion or toy, and sometimes tries it with the girls. And although he is not aggressive, he is very dominant. So I don't know the steroid is affecting him or not.

jenny, is your cat on prednisone long term? The reason I ask is because ever since I've taken Zorro off the steroids, his limp seems to be coming back. I'm worried that he's going to have to be on something long term and that it might have some ill effects. The prednisone worked great while he was on it, but I don't think it fixed the problem like we were hoping.

I don't know what his dosage of Prednisone was, but one of the side effects for cats is behavioral changes. Prednisone also weakens the immune system, risk of infection is much higher. Could the dosage have been a little high for him?

goth, what is going on with your cat that prednisone was prescribed in the first place? prednisone is a "steriod" and usually only used as a last resort.

Originally Posted by gothicangel69

jenny, is your cat on prednisone long term? The reason I ask is because ever since I've taken Zorro off the steroids, his limp seems to be coming back. I'm worried that he's going to have to be on something long term and that it might have some ill effects. The prednisone worked great while he was on it, but I don't think it fixed the problem like we were hoping.

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prednisone is an anti-inflammatory medication, a.k.a., steriod. it is not a cure at all. it will not "fix" a problem. it only relieves/reduces pain. it is not a "cure".

He was on 1 pill twice a day for three days, then 1/2 pill twice a day for 14 days, then 1/2 pill once a day for 14 days. (The bottle says 5 mg tablets)
He was put on them because of a collapsed disk in his back. There was a ton of swelling and he wasn't able to walk. His vet was hoping the if we got the swelling down, then he might be ok. The prednisone worked great while he was on it, his limp seems to have come back a bit in the last week, but it hasn't gotten any worse yet, so I'm just monitoring it.
The meds did weaken his immune system. He has a nasty infection inside one of the sockets on his front paw(the 'thumb'). He's been on clavamox now for nine days. Its working a little, but the infection is still there. He only has one day left, so the vet will probably have to remove the nail to get rid of the infection. (He thinks something is caught up in the socket)
His regular personality seems to be coming back. He hasn't had any freak moments in the last two days. I'm hoping it was just the prednisone. I hope he doesn't need to go back on it, because I he already has a bad immune system and his vet bills are starting to get really high. (In the last month and a half, I've spent over $600 on him, not to mention he's probably going to need a dental cleaning in the next month...another couple hundred...and surgery to remove that nail...at least a hundred) I'm almost at my wits end with him. Its getting very hard to come up with all the money he needs for vet bills.

I can imagine your frustration between constantly worried about him and all the other things popping up........That is a pretty serious problem and sounds like it was treated appropriately. I would keep an eye on him, he could have caused some irritation to the disk by running around like a nut for a week! I wouldn't think that it would be completely healed in a month any way, but the trick was probably to stimulate the healing process by reducing the swelling. Unfortunately he developed an infection in his paw which is the focus of his immune system.....Is his limp possibly favoring the paw?

Unfortunately not. The limp is favoring one of his back legs (which means its his back again).
The vet said that it won't be fully healed for another 6 months at the very least(if he lives that long. We're only expecting another year or so out of him, but you never know...)
I know it probably hurts because he won't stop running around like an idiot, lol. Even locking him in a room doesn't help(he's been locked in our room for well over a month now)

Originally Posted by gothicangel69

Unfortunately not. The limp is favoring one of his back legs (which means its his back again).
The vet said that it won't be fully healed for another 6 months at the very least(if he lives that long. We're only expecting another year or so out of him, but you never know...)
I know it probably hurts because he won't stop running around like an idiot, lol. Even locking him in a room doesn't help(he's been locked in our room for well over a month now)

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That is sad . Does catnip make him hyper or calm him down.....Maia passes out on the stuff

Lol, he likes to eat it, then gets the munchies.