I found the page, but no list of banned drugs. I sent an email to the Veterinary Chair, though.
I've not taken him off of it, nor do I know how long he'd have to be off of it to be legit. My vet said I could try, that he might stay sound, but I've said 'don't fix it if it ain't broke. the pills are easy to administer, can be varied if I think he needs more or less on a given day and are not expensive. I can give him as many as 25 according to the prescription, I usually give him 15 morning and 10 at night. Sometimes a few extra at night if he's worked hard.
What is the effective ingredient in the pills, do you know? There may be something that can replace it.