HDCN Article Review/Hyperlink

Levine BS, Song M

Pharmacokinetics and efficiency of pulse oral versus intravenous calcitriol in hemodialysis patients

J Am Soc Nephrol (Mar) 7:488-496 1996

The authors investigated the pharmacokinetics of calcitriol in 16 hemodialysis patients randomized to receive it by either the oral or IV route. Patients received 2 ug after each dialysis for 3 weeks. Kinetic studies were done after the 2nd and 8th dialysis. With the IV route, there were greater peak levels and areas under the curve up to 1 hr post administration. Thereafter, the areas under the curve were similar as were the plasma half-lives. Overall, the plasma half-lives were shorter during the second study.

Fifteen patients were successfully randomized to receive either oral or IV calcitriol for 21 weeks to compare their clinical efficacy. Serum calcium levels increased and PTH levels decreased to a similar degree in both groups. Similarly, the incidence of hypercalcemia and high Ca x P product was the same. The mean dose of calcitriol was 2 ug in each group. The authors conclude that pulse oral and IV calcitriol are equally efficacious in suppressing PTH levels in hemodialysis patients despite higher peak calcitriol values seen with the IV route.

Comment: The study largely confirms and extends prior studies. See Clin Nephrol 40:216-220, 1993 and Kidney Int 45:1710-1721, 1994. Well written discussion section. (James A. Delmez, M.D., Washington University at St. Louis)