Introduction: Losartan potassium, an orally active, highly selective AT1 angiotensin II receptor inhibitor, effectively reduces blood pressure by direct receptor blockade, thereby lessening the likelihood of angiotensin converting enzyme (ACE) inhibitor-associated side effects such as dry cough or possibly angioedema.
Study design: In this multinational, double-blind, randomized, parallel study, the efficacy and tolerability of once-daily losartan (50 mg) versus once-daily ACE inhibitor (captopril; 50 mg) was evaluated in 163 patients with mild to moderate hypertension. Non-responders after a 6-week treatment period had the dosage doubled for both study drugs until the end of study (week 12).
Results: Mean reductions in trough sitting diastolic blood pressure were significantly greater in the losartan group at week 6 (7.8 mmHg) and week 12 (9.1 mmHg) than in the captopril group (5.2 and 5.7 mmHg, respectively). Losartan and captopril were well tolerated. Headache was the most common adverse event reported in both groups.
Conclusions: It was concluded that a once-daily administration of losartan was significantly more effective in this study in lowering sitting diastolic blood pressure than once-daily administration of captopril in patients with mild to moderate essential hypertension. Both losartan and captopril regimes were well tolerated.