Hello dear user! Thank you for using healthcaremagic. I have read carefully your query and understand your concerns. I think you should choose an appropriate antibiotic for your tooth infection. Bactrim(sulfamethoxazole+trimethoprim) is a good antibiotic but the best effect of it are in gastrointestinal and urinary infections. I would suggest you another antibiotic that is sensitive to many kind of infections and has good effects in tooth infections like Klarithromycin twice daily. To manage the pain use painkiller like ibuprofen every 5-6 hours. Take them after the meals and with a big amount of water to diminish side effects of antibiotics. After some days of treatment consult a dentist to deal with the tooth. Please feel free to ask us again. I would be happy to answer again. If you are satisfied please kindly rate this answer as helpful. Wishing all the best, DR ERIOL.