Common side effects may include a depletion of sodium, folic acid, and calcium, nausea, vomiting, diarrhea, headache, dizziness, fatigue, and dry mouth.

Serious side effects may include heart palpitations, tingling/numbness, fever, chills, sore throat, rash, and back pain.

Triamterene directly blocks the epithelial sodium channel[4] (ENaC) on the lumen side of the kidney collecting tubule.

Triamterene is commonly prepared in combination with hydrochlorothiazide for treatment of hypertension (high blood pressure) and edema (water retention).

This combination is in a class of medications called diuretics or 'water pills', and causes the kidneys to get rid of the body's unneeded water and sodium through the urine.

[10][11] In 1986 Dyazide was the most prescribed drug in the US and had $325 million in sales, making it SmithKline Beckman's second-biggest seller behind Tagamet.

[21] Mylan's patents on the drug were declared invalid in court, and its marketing exclusivity expired in 1987, prompting a rush of generic competition and litigation by two of them, American Therapeutics Inc. and Vitarine Pharmaceuticals, with the FDA.