The pharmacokinetics and cardiovascular effects of the calcium entry blocker nisoldipine (10 mg twice daily) were studied in 6 patients with renal failure (creatinine clearance 23 +/- 9 ml/min) and 6 healthy control subjects after a single dose and 1 week of oral administration. No significant differences in elimination half-life, area under the concentration/time curve, peak plasma drug concentration and time to reach that peak were observed between renal patients and control subjects, and between single-dose and short term administration. The decrease in systolic blood pressure and increase in heart rate were similar in both groups, but the decrease in diastolic blood pressure was more pronounced in the patients. This can be explained by increased haemodynamic sensitivity for nisoldipine. Adverse effects were mainly restricted to the first day of administration.