Serious toothache in molar need a root canal. what can i take to ease the pain till next monday when i see dentist?

Depends n....: Mainly your pain level... But for over the counter type of meds, ; if you dont have stomach issues, generally you can take 600 or 800 mg. Of Motrin (same as advil , or ibuprofen) up to 4 times a day (max. Allowable and safe daily ose is 3200 mg.). Make sure you take them with food or after food (not on empty stomach) . For prescription meds you need to cantact your treating dentist. Good luck.

If I were you: If i were you i would request your dentist see you tomorrow on an emergency basis to start treating the tooth and relieve the pain. If your dentist can't do that, i would consider seeing another dentist. If waiting until monday was as a result of your scheduling, i would consider my priorities and make other arrangements. That's me. If you want to wait, otc pain medication is all that you can do.