SIDE EFFECTS: The most common side effects associated with trimethoprim are gastrointestinal. They include loss of appetite, nausea, vomiting, diarrhea, abdominal pain, abnormal taste, and swelling of the tongue. Taking trimethoprim with food may reduce some of these side effects.

Trimethoprim may cause anemia due to a deficiency of folic acid. The anemia usually is mild and resolves when the trimethoprim is stopped. Patients who are folate-deficient, such as malnourished, alcoholic, geriatric, or pregnant patients, may be at greater risk for developing anemia with trimethoprim. Warning signs of anemia include white or bluish fingernails and unusual tiredness and weakness. Prolonged therapy can result in low platelet counts, low white blood cell counts, and other toxic effects on the blood cells.

The most common side effects related to the skin are rash and itching. Rarely, the rash can progress to peeling or blistering. Some patients have photosensitivity reactions, that is, they develop skin rashes on parts of their body that are exposed to the sun.

Reference: FDA Prescribing Information

Suggested Reading by Our Doctors

• Drug Interactions - Learn about potential drug interactions you may be exposed to. Drug interactions can occur with prescription drugs, OTC medication, vitamins, herbs, and supplements.
• Liver Blood Tests - Learn about liver blood tests used to detect liver damage disease such as fatty liver, cirrhosis, hepatitis, Tylenol liver damage, and more. This includes measuring the aminotransferases enzymes (AST and ALT levels)
• Urinary Tract Infection (UTI In Adults) - Learn about urinary tract infection causes, symptoms, signs, diagnosis and treatment of UTIs in men and women. Antibiotics may be used to treat recurrent bladder infections.

Read more trimethoprim related articles »

Latest Medical News

• Preventive Antibiotics Help Some Kids Fend Off Urinary Infections