Effects of diltiazem on renal function

We planned to investigate the effect of diltiazem on urine volume, urine sodium (Na+) and potassium (K+) excretion and glomerular filtration rate (GFR). Twenty healthy men, aged between 23 and 36 (mean age: 29 ± 0.87) were examined. A double - blind placebo controlled study was completed by weekly intervals in 3 periods. In each period, first day no drug was given, the second day placebo, the third day diltiazem (30 mg or 60 mg) or placebo was given. In the first 6 hour period following diltiazem 30 or 60 mg administration, increases in GFR (p 0.05). In the next 18 hour period, we observed that diltiazem did not affect the excretion of K+ urine volume and GFR (p> 0.05), but increased the excretion of Na+ (p<0.05).