Title: Clinical Usefulness of Losartan, an Angiotensin II Receptor Antagonist with a Uricosuric Effect, and the Influence of Aspirin on the Effect in Hypertensive Patients with Hyperuricemia
Abstract: Losartan, an angiotensin II receptor antagonist, has been reported to decrease the serum uric acid (SUA) level and increase the urinary excretion of uric acid. This action might be beneficial in hypertensive patients, who frequently suffer from hyperuricemia and sometimes gout. The aims of this study were to evaluate the uricosuric effect of losartan on hypertensive patients with hyperuricemia (SUA>7mg/dL), identify factors that influence the uricosuric effect of losartan, and determine whether or not medication of hyperuricemia with other drugs is necessary.A total of 28 hypertensive patients with hyperuricemia were studied retrospectively (no medication for hyperuricemia). Aspirin was found to be a factor that influences the uricosuric effect of losartan (p= 0.088). In hypertensive patients with hyperuricemia treated with aspirin medication (N = 7), losartan did not significantly decrease the SUA levels from 8.56 ± 0.66 to 8. 29 ± 0. 40mg/dL. Moreover, none of the patients had their SUA controlled of a normal level by losartan. In hypertensive patients with mild hyperuricemia (7.0≤SUA<8.0, without aspirin medication, N=12), losartan decreased the SUA level significantly from 7.35±0.08 to 6.85±0.32mg/dL. In five of the 12 patients, losartan controlled SUA at a normal level. Therefore, when losartan is prescribed to these patients, the treatment of mild hyperuricemia may not require the use of other drugs. In hypertensive patients with severe hyperuricemia (8.0≤SUA, without aspirin medication, N=9), losartan decreased the SUA level significantly from 9.55±0.57 to 8.21±0.35mg/dL. However, none of the patients had their SUA controlled at a normal level by losartan. Although the decrease of SUA level by losartan can be expected in these patients, the control of SUA at a normal level could not be expected. Therefore, the treatment of hyperuricemia with other drugs is considered to be required for these patients. Losartan may be a useful therapeutic drug to control the blood pressure and SUA levels in hypertensive patients with mild hyperuricemia