Bactrim is a comlex of trimethoprim and sulfamethoxazole. It's antibiotic. Bactrim kills infectual bacteria, which in the body. The main target of it is to fight different kinds of infections. They are infection of urinary tract, ear infection, Pneumocystis carinii pneumonia, diarrhea, bronchitis. It may also be useful in other cases, which are not described here. If you have an allergy to Bactrim or to some components it consists of don't use it. If you have an allergy to some drugs related to Bactrim you should also avoid using of it. They are trimethoprim and sulfamethoxazole. You should be careful in using it if you have an liver disease, kidney problems, asthma, AIDS, a folic acid deficiency and others. This drug makes your skin sensitive to the lihgt of the sun. You may use this medicine alone or in complex with others drugs. It's strongly recommended to not use it with prescription and nonprescription drugs, dietary medicine, herbal drugs. If you are going to be pregnant or already pregnant you should talk about using of Bactrim with your doctor. You should also ask your doctor if this medicine could be compound with other drugs you are taking. You should have consultancy with your doctor before using Bactrim to prevent nagative effects.