Triamterene is a synthetic antikaliuretic agent that exerts its mechanism of action by inhibition of sodium ions in exchange for potassium and hydrogen ions on the distal renal tubule. This puts triamterene in a class of drugs called "potassium sparing" diuretics that are commonly used to reduce the amount of water in the body. Triamterene is often combined with hydrochlorothiazide to product a remedy that is used to regulate blood pressure. Side effects include skin rash and itching, shortness of breath, fever or chills, and painful or difficult urination.