Yeah, unfortunately when a tolerance is built up, it may be necessary to increase the dose or switch to a stronger drug such as morphine. Don't ask for it by name though or they will think you are "drug seeking", sigh. Drug abusers have made it harder for those who genuinely need adequate pain relief to get it. Best to just stress to the doctor that the current drug is not helping enough and say how much the pain is affecting your life. A good doctor will respond accordingly, a bad one will basically imply that you should suck it up. Grrr.
Also, I forgot about paracetamol. It can be very effective for pain if you take it 4 times a day for at least a few days, and it's side effect profile is very small.