LOSARTAN POTASSIUM LOWERS BLOOD-PRESSURE MEASURED BY AMBULATORY BLOOD-PRESSURE MONITORING

Objectives: To determine the blood pressure lowering effect and safety of losartan potassium 50 mg once or twice daily, or 100 mg once daily , using 24-h ambulatory blood pressure monitoring and conventional tro ugh clinic blood pressure. Design: Multicenter, double-blind, randomiz ed, parallel, placebo-controlled trial. Setting: Nine sites in univers ity hospitals and urban centers in the United States. Patients: 122 m ild to moderate hypertensive adult non-black men and women, 21 years o f age and older, who were within 30% of their ideal body weight. Inter vention: Qualification required a mean 24-h ambulatory blood pressure measurement of greater than or equal to 85 mmHg and a sitting diastoli c blood pressure of 95-115 mmHg. Subjects were then randomized to plac ebo or losartan potassium in three different dose regimens. Clinic blo od pressure evaluations: Trough blood pressure was measured by trained observers using standardized methods, and ambulatory blood pressure m easurements were obtained for 26 h using a SpaceLabs Model 90207 monit or. Results: All doses of losartan potassium significantly decreased m ean systolic 24-h ambulatory blood pressure (range -9.4 to -14.2 mmHg; P less than or equal to 0.01) and mean diastolic 24-h ambulatory bloo d pressure (range -5.6 to -9.0 mmHg; P less than or equal to 0.01) com pared with placebo. All decreases were significantly different from pl acebo. The 24-h blood pressure profiles revealed a smooth, sustained a ntihypertensive effect of losartan potassium at all doses. Similar red uctions in blood pressure were observed using trough clinic measuremen ts. There were no significant differences in overall clinical adverse experiences between treatment groups. There were no significant change s in heart rate, body weight, electrocardiograms or mean laboratory me asurements. Conclusions: Losartan potassium, the first of a new class of potent and specific AT(1)-selective, non-peptide, angiotensin II an tagonists, significantly reduces mean 24-h ambulatory blood pressure a nd trough clinic sitting blood pressure, and is well tolerated.