Metacam when it's marketed for dogs, Meloxicam when it's in pill form for humans(My Goldie takes the pill form, substantially cheaper when needed on a long term basis.) If this is the drug you meant, he will need to see a vet. It's prescription only.

edited...just noticed this was for a cat, not a dog. Metacam is not technically approved for use in cats. My vet gives it on a short term basis only for cats. Cats process NSAIDs very differently from dogs.