Amiloride Demonstrates Similar Effectiveness to Spironolactone in Treating Resistant Hypertension

Recent research led by Yonsei University College of Medicine has revealed that amiloride, a potassium-sparing diuretic, is as effective as spironolactone in reducing systolic blood pressure (SBP) in patients with resistant hypertension over a 12-week period. Resistant hypertension affects approximately 10% of individuals with high blood pressure and is linked to more adverse health outcomes compared to nonresistant cases.

Spironolactone is typically considered a fourth-line treatment option after other medications such as renin-angiotensin system inhibitors, calcium channel blockers, and thiazide diuretics fail to control blood pressure. However, its long-term use can be limited due to side effects like hyperkalemia and hormonal disturbances. Amiloride offers a promising alternative as it shares the diuretic action but without the hormonal side effects.

The study, published in JAMA under the title "Spironolactone vs Amiloride for Resistant Hypertension: A Randomized Clinical Trial," involved 118 participants across 14 South Korean hospitals. Patients, aged between 19 and 75, had persistent hypertension despite a four-week run-in period on a triple therapy combination. Participants were randomized to receive either 12.5 mg of spironolactone or 5 mg of amiloride daily. Dosage adjustments were permitted after four weeks if blood pressure remained elevated.

Results showed that after 12 weeks, the amiloride group experienced an average SBP reduction of 13.6 mm Hg, while the spironolactone group saw a reduction of 14.7 mm Hg. The difference between the two groups was within the predefined noninferiority margin, indicating similar efficacy. Around 66.1% of participants on amiloride achieved target blood pressure levels below 130 mm Hg, compared to 55.2% on spironolactone. There was one case of hyperkalemia leading to discontinuation in the amiloride group, but no instances of gynecomastia were reported.

The findings suggest that amiloride may serve as a viable alternative to spironolactone, particularly for patients who are intolerant of its hormonal side effects. This could further expand options for managing resistant hypertension effectively.

Source: Medical Xpress