^^ definitely agree with the tubigrip idea. I have RSI in both wrists and exams can be a nightmare, but wearing a good, firm tubigrip can really help relieve the pain. It's also a good idea to wear it generally for the exam period - that can be annoying but I find that the extra support seems to stop the pain from getting really bad.
I was once told (by a hospital doctor, when I'd badly sprained my wrist) that you can take paracetamol and ibuprofen 'together', in that you take one dose of paracetamol and then when you're due another dose, take ibuprofen instead and so on. Apparently this works really well as a painkiller, but if you've never tried it I'd be wary of doing it before an exam. I also don't know how safe it is - has anyone else ever heard this?