Hello, Read your query , understand your concern as you have severe toothache dont worry this pain can be due to still infection is present at periapical region of tooth so as your doctor has advised you re-rct and as you are asking for painkiller tablets for toothache, you can take then one tablet like Diclofenac sodium, flexon or ketorol dt by consulting your local doctor, as one tablet sufficient to control your pain for atleast 6 hours . Dont take analgesic (pain killer) many tablets , as it can harm you , consult your dentist and go for treatment as this painkiller gives you temporary relief . Hope this will help you. If you have further query , I will be happy to help. Regards, Dr. Priyanka tiwari