Renal failure with potassium-sparing diuretics.

In one year 19 patients aged 73 SD 8 yr were referred with renal failure (plasma creatinine 0.14-0.52 mmol/l; urea 7.9-39.5 mmol/l; potassium 2.9-6.1 mmol/l, who were taking amiloride/hydrochlorothiazide (ten), amiloride alone (one) or triamterene/hydrochlorothiazide (eight). Six patients were taking other diuretics. Sixteen patients were being treated for hypertension and three for fluid retention; five hypertensive patients were also taking non-steroidal anti-inflammatory drugs (NSAID). Four patients were hypokalaemic, three were volume-depleted. All potassium-sparing diuretics and NSAID were stopped (four required another diuretic). Six-100 days later renal function was improved in 17 patients, unchanged in one and one patient had died of uraemia. Blood pressure was satisfactory on no therapy in 11 patients and two normotensive patients were oedema-free. In elderly patients with renal impairment potassium-sparing diuretics may cause renal failure, sometimes secondary to hypovolaemia, and NSAID may potentiate the effect.