[Raistlin]

I found Naproxen innefective at first when I was prescribed it a few months back, after a few days though it really started to kick in - that made me wonder if the effects might be cumulative rather than immediate.

Also it could be that Naproxen has actually been proven more effective at dealing with the specific type of pain, or in the specific area that you're having problems with.

Finally, it could be that your doctor is a moron that hasn't got a clue what he's talking about.

If you're seriously concerned you should go and see a different doctor, explain your concerns to them, and get a second opinion.