Why would anyone want to needlessly take a painkiller before playing? I don't think it's a wise idea generally speaking (there are exceptions). When a part of your body is in pain, it's telling you that you should stop the activity or reduce it. Taking a painkiller beforehand can make you lose "information" from your body and lead to injury. I think it's better to avoid painkillers as much as possible.
That being said, I'm around 30 and although I don't take painkillers because joints are still in good shape... I end up taking them more usually than I'd like because of migraines. But I try to use as little as possible both in dosage and number of pills. Usually something around 650mg of paracetamol tames it a bit. If it's stronger I must aim for a gram, and not always with good result.
And, as a curiosity, I've observed that for tennis, there's a great difference between my normal days, my migraine days and the immediate days before a migraine attack:
On normal days... I'm ok. I run, I concentrate like any regular guy.
On the migraine ones I feel absolutely weak and get tired very easily. The racquet weighs a ton and I can't seem to find any kind of precision or power regulation: either I hit really short balls or I hit really long balls.
But the pre-migraine days are really funny. Some days I start seeing "auras" and I can't properly watch the ball for a while. Some days I feel weak, like in a fever. Both things put me in a pretty defensive stance. But some other days I feel super energized, like after having had 5 energy drinks. These latter days I have to hold myself back, since I tend to attack in a "suicidal" way and try to finish points at the net and in two or three strokes at most. The problem is that my energy fades at a random moment and I feel drained. Whenever any of these things happen I know I must take a painkiller. But I don't always do and pay the consequences later...