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

Objective: This international, multicentre, 16-week, double-blind, parallel , two-arm, randomised study was conducted to compare the effects on blood p ressure and tolerability of the angiotensin II (Ang II) ATI receptor antago nist 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 sittin g 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 r ange of 20 to 60 ml/min/1.73m(2) Interventions: The initial 4-week placebo period was followed by 12 weeks o f treatment with losartan 50mg, possibly titrated to 100mg, once daily (gro up 1, n = 64) or 25mg captopril, possibly titrated to 50mg, twice daily (gr oup 2, n = 65). Main Outcome Measures: Antihypertensive efficacy was evaluated by the reduc tion of blood pressure (BP) after 12 weeks. The main efficacy measurement w as the SiDBP. Secondary end-points included sitting systolic and standing B P, creatinine clearance, total proteinuria, total cholesterol, triglyceride s and high density lipoprotein cholesterol levels. Tolerability was assesse d by the incidence of adverse events and by clinical and laboratory tolerab ility 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 pressur e (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 statist ically significant difference between the two groups, which was also consis tent with the other parameters recorded. In the losartan group, total prote inuria was significantly decreased at the end of the study. Creatinine clea rance, lipids and the proportion of patients with clinical adverse experien ces showed no remarkable changes at all in the two groups, although such ex periences affecting the respiratory system, especially cough, appeal ed sig nificantly more often (p < 0.034) in captopril-treated patients. Conclusions: Losartan could be as suitable: as captopril as an antihyperten sive agent in costs where renal function is impaired.