[LunaTheHamster1]

If it is pain relief for a chronic condition, then your hamster could may well be on it for life but I would ring your vet to get confirmation of this. Also, if you need a repeat prescription you will probably need to speak to them anyway.
Personally I buy my hamster medicine from the vets as buying online you don't always know where it is coming from or if it is knock off. I guess it would depend where abouts online oyu are buying it from, also you would need to make sure it was the right strength etc(I don't know if metacam comes in different strengths)

For short term, I would wake my hamster up to give medicine, for my hamsters that have been on baytrill or metacam for long term i.e for illnesses related to old age I put it in babyfood and just slip it into where they sleep and they just eat it when they wake up. You do need to make sure your hamster is eating the babyfood with the medicine in it though.