Effect of combined administration of furosemide and aspirin on urinary urate excretion in man.

Furosemide (20 mg) was administered intravenously to 7 healthy volunteers, before and after 4 days of oral administration of aspirin in uricosuric dosage (1 g daily). Aspirin prevented the decrease in urinary urate excretion induced by furosemide, without interfering with its natriuretic action. This finding is suggested to be the result of the opposite and independent effects of the two drugs on tubular reabsorption of urate.