What is Bactrim?
Bactrim contains a combination of sulfamethoxazole and trimethoprim. Sulfamethoxazole and trimethoprim are are both antibiotics that treat different types of infection caused by bacteria.
Bactrim is used to treat ear infections, urinary tract infections, bronchitis, traveler’s diarrhea, shigellosis, and Pneumocystis jiroveci pneumonia.
Bactrim may also be used for purposes not listed in this medication guide.
You should not use Bactrim if you have severe liver or kidney disease, anemia caused by folic acid deficiency, or a history of low blood platelets caused by taking trimethoprim or any sulfa drug.
Before taking this medicine
You should not use Bactrim if you are allergic to sulfamethoxazole or trimethoprim, or if you have:
severe liver or kidney disease;
anemia (low red blood cells) caused by folic acid deficiency; or
a history of low blood platelets caused by taking trimethoprim or any sulfa drug.
To make sure Bactrim is safe for you, tell your doctor if you have:
kidney or liver disease;
a folic acid deficiency;
asthma or severe allergies;
a thyroid disorder;
HIV or AIDS;
porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system);
a glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency); or
if you are malnourished.
FDA pregnancy category D. Do not use Bactrim if you are pregnant. It could harm the unborn baby. Use effective birth control, and tell your doctor if you become pregnant during treatment.
See also: Pregnancy and breastfeeding warnings (in more detail)
Sulfamethoxazole and trimethoprim can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
Do not give Bactrim to a child younger than 2 months old.
Serious side effects may be more likely in older adults, especially those who take other medications such as digoxin or certain diuretics.