The kinetics of verapamil during chronic oral therapy were evaluated in a maintenance hemodialysis patient. The elimination half-lives of verapamil and its major metabolite norverapamil were 3.8 and 15.2 h. The former is shorter, while the latter is similar to that in patients with normal renal function. Hemodialysis did not affect drug half-life, and neither drug could be detected in the dialysate. Our studies suggest that verapamil kinetics are altered in end-stage renal disease and that hemodialysis does not remove significant amounts of the drug or its metabolite.