Effects of triamterene and amiloride on urinary sediment in hypertensive patients taking hydrochlorothiazide.

In a crossover study of 26 hypertensive patients, the effects of triamterene (50 mg/day) and amiloride (5 mg/day) on urinary sediment were compared. Each drug was given for one month and all patients also received hydrochlorothiazide (50 mg/day). An abnormal urinary sediment--evident grossly as a reddish-brown precipitate after routine staining procedures and microscopically as characteristic reddish-brown crystals and casts, as previously described--was identified in 14 of 26 (54%) triamterene urine samples but in none of the amiloride samples. Results of renal function tests were similar for both drugs. In a clinic population of more than 1000 hypertensive patients over 4 years, interstitial nephritis was diagnosed in 4, all of whom were taking a triamterene-containing combination diuretic. It is possible that triamterene is a factor in the aetiology of interstitial nephritis.

RCT Entities:   Population Interventions Outcomes