P-440: Losartan but not irbesartan reduces serum uric acid in hypertensive patients with hyperuricemia and/or gout

Losartan has unique uricosuric properties and has been shown to decrease serum uric acid (SUA) levels in normal subjects as well as in hypertensive patients. The purpose of the present study was to compare the effects of losartan and irbesartan on serum uric acid in hypertensive hyperuricemic patients with or without gout. Twelve hyperuricemic (SUA>420mmol/L), hypertensive patients (mean age: 58 yr) participated in this randomized, double-blind, crossover study. After a 3-week run-in period during which patients received enalapril 20 mg o.d, patients were randomized to receive either losartan 50 mg o.d for 4 weeks followed by losartan 50 mg bid for another 4 week period or irbesartan 150 mg o.d followed by irbesartan 150 mg bid for 4 weeks. The losartan and irbesartan phases were separated by 3 weeks of the ACE inhibitor. All drugs were provided in an electronic pill container allowing to monitor compliance (MEMS system). Losartan decreased SUA significantly from 539±28 mmol/L to 490±22 mmol/L (p1 month). Hence, the uricosuric effect tends to decrease with time as SUA is reduced. Increasing the dose of losartan to 50 mg bid does not appear to induce a further decrease in serum uric aci