nakedmolerat: if you go to emergency, they should be able to give you something stronger for tonight until you see a dentist tomorrow.
Don't go to emergency. It's not an emergency. If you're really hurting, go to your nearest 24 hour medical centre (e.g. http://www.whitecross.co.nz/) - but as previously mentioned, unfortunately the solution is likely to be with a dentist +/- antibiotics rather than throwing analgesics at it.