The redness, swelling and pain at the back of the big teeth are mostly caused by gingivitis, wisdom teeth pericoronitis, etc., which can be improved by medication and surgical treatment. 1. Gingivitis: you can apply iodized glycerin or chlorhexidine acetate gargle to reduce swelling and pain. You can also take penicillin, cephalosporin, nitroimidazole antibiotics for treatment, such as amoxicillin, cefuroxime, metronidazole and so on. 2. Wisdom tooth pericoronitis: first of all, the local rinse on the iodine glycerin, there is an abscess formation needs to be incised and drained, at the same time can comply with the doctor’s instructions to use the above antimicrobial drugs to reduce the swelling, can be treated with surgery, such as wisdom teeth extraction. These drugs can have different degrees of adverse reactions, such as nausea, vomiting, skin rash, etc., in the use of, need to be used under the guidance of a doctor.