Bactrim, or SMX-TMP, is a combination of a sulfonamide antibiotic and a second antibiotic, trimethoprim (Sulfamethoxazole And Trimethoprim). It is used to treat bacterial infections. It is also used to prevent infections in people who are at risk. It will not work for colds, flu, or other viral infections.
If you are sensitive to or have ever had an allergic reaction to trimethoprim, sulfamethoxazole, or other sulfa drugs, you should not take this medication. Make sure that your doctor is aware of any drug reactions that you have experienced. Unless you are directed to do so by your doctor, do not take this medication if you have been diagnosed as having megaloblastic anemia, which is a blood disorder due to a deficiency of folic acid. This Other, less severe (but more common) side effects are: headache, dizziness or fatigue; nausea, vomiting, diarrhea, decreased appetite; weakness; increased sensitivity to direct sunlight.
Side effects that you should report to your doctor or health care professional as soon as possible: allergic reactions like skin rash or hives, swelling of the face, lips, or tongue, breathing problems, fever or chills, sore throat, irregular heartbeat, chest pain, joint or muscle pain, pain or difficulty passing urine, red pinpoint spots on skin, redness, blistering, peeling or loosening of the skin, including inside the mouth, unusual bleeding or bruising, unusually weak or tired, yellowing of the eyes or skin. If Bactrim is taken with certain other drugs, the effects of either could be increased, decreased, or altered. If you suspect an overdose of Bactrim, seek emergency medical attention immediately. Ask your doctor to tell you how, when and how much Bactrim you should take on a regular basis. In order to get the best results from you treatment with Bactrim, you must try to take this drug on a regular basis.