Buspirone for cats

Does anyone give Buspirone to their kitty to help eliminate urine spraying?
Bud, who is neuteured since 6 months old, has been marking his territory for a few years. He has been on Diazepam for about 3 years. It helps but is not entirely successful. Yesterday I asked the vet to prescribe Buspirone. I gave him 5 mg last night and another 5 mg this morning. I also have to gradually ween him off the Diazepam. Well, about an hour after taking it this morning, he has become really agressive towards the other cats. He's acting really strange and really nervous. I know that taking a new medication takes getting used to but it's nerve wrecking to watch him. The vet said that their was no danger mixing the two medications in order to ween him off the Diazepam.
The vet had suggested raising the dose of Diazepam to see if that would help instead of changing medications. I was hesitant because I'm already not at ease giving him valium. But now I think I will have to because he has no weird side effects with Diazepam.
Your intake would be so appreciated. Thank you.

Good grief! My 210 pound husband only takes half a 15mg Buspar at a time! So you're giving him almost as much! Maybe try halving the dose at least and see what that does.

Rosehawke, the pill is 10 mg and I gave him half the dose as the vet suggested. I investigated many places on the internet and the recommended dose mentionned is what the vet suggested.
In any case, I AM NOT going to give him this medication again. Since this morning the medication has worn off and he seems O.K. now. I will, however, continue with the Diazepam which doesn't cause any worrisome side effects. He sometimes just does the action of marking with no urine sprayed and other times he does squirt. I'll just continue cleaning up after him when that happens.

Catgal, I would stick with the Valium. I am a pharmacist and think that if a medication has that effect on your kitty it probably is not the right medication for him or not the correct dosage. Every cat just as every person's system is different and metabolizes medications differently. You should also (depending on how long he has been taking the medication) slowly ween off of a medication not stop suddenly. That can turn out to be harmful. When your dealing with medication it is always better to be safe than sorry.

Mizzcat, thank you for your advice. I am definitely going to stick with the Valium. He cannot be without this medication because his urine spraying gets out of control without it.