We put our cat on Cosequin. Quite reasonable price (Amazon) for cats, but for some reason the Cosequin for dogs is so much more expensive.
In about 3-4 weeks, I had my old cat back. No more problems jumping up or moving around. Our vet says it works for some animals and not for others. But it seems like it should be the first thing you try, before resorting to a prescription med.