Tolerability and antihypertensive efficacy of losartan vs captopril in patients with mild to moderate hypertension and impaired renal function A randomised, double-blind, parallel study

Abstract

Objective: This international, multicentre, 16-week, double-blind, parallel, two-arm, randomised study was conducted to compare the effects on blood pressure and tolerability of the angiotensin II (Ang II) ATI receptor antagonist losartan and captopril in patients with mild to moderate hypertension and impaired renal function. Patients: 102 of the total of 129 patients (mean age 55.2 years) having any form of secondary hypertension except renal artery stenosis were recruited from 18 centres in 10 countries. Mild hypertension was defined as a sitting diastolic blood pressure (SiDBP) of 95 to 105mm Hg, moderate hypertension as 106 to 115mm Hg, while creatinine clearance was required to be in the range of 20 to 60 ml/min/1.73m(2) Interventions: The initial 4-week placebo period was followed by 12 weeks of treatment with losartan 50mg, possibly titrated to 100mg, once daily (group 1, n = 64) or 25mg captopril, possibly titrated to 50mg, twice daily (group 2, n = 65). Main Outcome Measures: Antihypertensive efficacy was evaluated by the reduction of blood pressure (BP) after 12 weeks. The main efficacy measurement was the SiDBP. Secondary end-points included sitting systolic and standing BP, creatinine clearance, total proteinuria, total cholesterol, triglycerides and high density lipoprotein cholesterol levels. Tolerability was assessed by the incidence of adverse events and by clinical and laboratory tolerability measurements. Results: After 12 weeks' administration of losartan a reduction of 12.2 +/- 10.2mm Hg in SiDBP and 15.5+/- 18.0mm Hg in sitting systolic blood pressure (SiSBP) was observed, compared with 11.2+/- 11.4mm Hg and 15.6+/- 20.6mm Hg, respectively, in captopril-treated patients. Thus, there was no statistically significant difference between the two groups, which was also consistent with the other parameters recorded. In the losartan group, total proteinuria was significantly decreased at the end of the study. Creatinine clearance, lipids and the proportion of patients with clinical adverse experiences showed no remarkable changes at all in the two groups, although such experiences affecting the respiratory system, especially cough, appeal ed significantly more often (p < 0.034) in captopril-treated patients. Conclusions: Losartan could be as suitable: as captopril as an antihypertensive agent in costs where renal function is impaired.