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What is the most important information I should know about sulfamethoxazole and trimethoprim?

You should not use this medication if you are allergic to sulfamethoxazole or trimethoprim, if you are pregnant or breast-feeding, or if you have anemia (lack of red blood cells) caused by folic acid deficiency.

Before using sulfamethoxazole and trimethoprim, tell your doctor if you have kidney or liver disease, a folic acid deficiency, asthma or severe allergies, AIDS, a glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency), or if you are malnourished.

Take this medication for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Sulfamethoxazole and trimethoprim will not treat a viral infection such as the common cold or flu.

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or has blood in it, call your doctor. Do not use any medicine to stop the diarrhea unless your doctor has told you to.

Avoid exposure to sunlight or artificial UV rays (sunlamps or tanning beds). Sulfamethoxazole and trimethoprim can make your skin more sensitive to sunlight and sunburn may result. Use a sunscreen (minimum SPF 15) and wear protective clothing if you must be out in the sun.

What is sulfamethoxazole and trimethoprim?

Sulfamethoxazole and trimethoprim are both antibiotics that treat different types of infection caused by bacteria.

The combination of sulfamethoxazole and trimethoprim is used to treat ear infections, urinary tract infections, bronchitis, traveler's diarrhea, and Pneumocystis carinii pneumonia.

Sulfamethoxazole and trimethoprim may also be used for other purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking sulfamethoxazole and trimethoprim?

You should not use this medication if you are allergic to sulfamethoxazole or trimethoprim, if you are pregnant or breast-feeding, or if you have anemia (lack of red blood cells) caused by folic acid deficiency.

If you have certain conditions, you may need a dose adjustment or special tests to safely use this medication. Before using sulfamethoxazole and trimethoprim, tell your doctor if you have:

• kidney or liver disease;

• a folic acid deficiency;

• asthma or severe allergies;

• AIDS;

• a glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency); or

• if you are malnourished.

FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment. Sulfamethoxazole and trimethoprim can pass into breast milk and may harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby. Do not give this medication to a child younger than 2 months old. Older adults may be more likely to have side effects while taking this medication.

How should I take sulfamethoxazole and trimethoprim?

Take this medication exactly as prescribed by your doctor. Do not take it in larger amounts or for longer than recommended. Follow the directions on your prescription label.

Measure liquid medicine with a special dose-measuring spoon or cup, not a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

Take this medication for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Sulfamethoxazole and trimethoprim will not treat a viral infection such as the common cold or flu. Drink plenty of fluids to prevent kidney stones while you are taking trimethoprim and sulfamethoxazole. Store the tablets and liquid at room temperature away from moisture, heat, and light.