Effect of eprosartan and losartan on uric acid metabolism in patients withessential hypertension

Objective The influence of angiotensin II AT-1 receptor antagonists on uric acid metabolism, and the potential differences among them with regard to t his effect, remains to be precisely established. This study was designed to compare the effects of losartan and eprosartan on uric acid metabolism in patients with mild to moderate essential hypertension. Design Randomized, double-blind, parallel-group study in hypertensive patie nts. Setting Outpatient clinic. Patients Following a 2- to 3-week single-blind placebo run-in period, 60 pa tients with sitting diastolic blood pressure greater than or equal to 95 an d less than or equal to 114 mmHg were randomized. Fifty-eight patients comp leted the study. Interventions Patients were randomized to receive losartan 50 mg or eprosar tan 600 mg once daily for 4 weeks. Main outcome measures The primary endpoint was the change in the ratio of u rinary uric acid/creatinine in the period 0-4 h of a 24 h urine collection after 4 weeks of treatment. Secondary endpoints included 24 h urinary uric acid excretion, as well as serum urate and antihypertensive efficacy, Results Mean urinary uric acid/creatinine changes from baseline were 0.14 ( day 1) and 0.11 (week 4) for losartan and -0.04 for eprosartan (at both day 1 and week 4; P< 0.01 between groups at both time-points). The mean increa se in 24 h urinary uric acid excretion with losartan was 0.7 mmo1/24 h (25% increase from baseline) at both day 1 and week 4. No significant differenc e was observed in the change of serum urate levels versus baseline between both treatment groups after 4 weeks (-23.4 and - 19.5 mu mol/l for losartan and eprosartan, respectively). Patients with hyperuricaemia in both treatm ent groups showed similar modifications of uric acid metabolism compared wi th non-hyperuricaemic subjects. Blood pressure control (sitting diastolic b lood pressure < 90 mmHg or <100 mmHg with a decrease of at least 10 mmHg fr om baseline) was achieved in 22 patients (73%) with eprosartan and in 16 (5 3%) with losartan, Conclusions Losartan increased uric acid excretion in hypertensive patients , whilst eprosartan did not, Neither AT-1 receptor antagonist substantially modified serum urate concentrations. J Hypertens 1999, 17:1033-1039 (C) Li ppincott Williams & Wilkins.