Triamterene for Blood Pressure Treatment

Primary Role and Efficacy

The European Society of Cardiology recommends triamterene as an adjunctive therapy when combined with thiazide diuretics to prevent hypokalemia while providing modest additional blood pressure reduction 1
The European Society of Cardiology does not list triamterene among primary antihypertensive agents, instead recommending ACE inhibitors, ARBs, calcium channel blockers, and thiazide/thiazide-like diuretics as first-line therapy 1

The European Society of Cardiology recommends considering adding triamterene to thiazide therapy when hypokalemia develops on thiazide monotherapy, patient requires continued diuretic therapy but cannot tolerate potassium supplementation, or resistant hypertension persists despite first-line agents and spironolactone is contraindicated or not tolerated 1, 2
In resistant hypertension, the European Society of Cardiology recommends a hierarchy of spironolactone, eplerenone, amiloride, triamterene, higher-dose thiazide, or loop diuretic 1

The standard combination is hydrochlorothiazide 25-50 mg with triamterene 37.5-50 mg once daily, with a maximum of HCTZ 50 mg and triamterene 100 mg daily 2

Check serum potassium, sodium, and magnesium within 1-2 weeks of initiation, then periodically during long-term therapy 2
Initial monitoring should occur 5-7 days after starting therapy, with subsequent monitoring every 5-7 days until potassium stabilizes, then at 3 months, and every 6 months thereafter 2, 4

Do not use triamterene when GFR <45 mL/min, baseline potassium >5.0 mEq/L, or concurrent potassium supplements or salt substitutes 2, 5
Use triamterene with extreme caution when combined with ACE inhibitors or ARBs, NSAIDs, or in elderly patients 2

In heart failure with reduced ejection fraction, the American Heart Association recommends aldosterone receptor antagonists over triamterene due to proven mortality benefit 3
Avoid triamterene entirely when GFR <45 mL/min, and in moderate CKD, loop diuretics are preferred over thiazide-type diuretics 2, 3, 5

For most hypertensive patients requiring a potassium-sparing diuretic, spironolactone 25-50 mg daily is preferred over triamterene due to superior evidence for cardiovascular outcomes 1, 3