COMPARISON OF THE EFFECTS OF ENALAPRIL AND THEOPHYLLINE ON POLYCYTHEMIA AFTER RENAL-TRANSPLANTATION

Posttransplant erythrocytosis (PTE) is a potentially serious complicat ion for which (apart from phlebotomy) two alternative treatments have been proposed: theophylline (Theo) and angiotensin-converting enzyme i nhibitors. We investigated 28 patients with PTE, who were assigned to 3 matched groups. Group 1 (10 patients) received 10 mg of Enalapril (E na)/day. After 2 months, mean hematocrit (Ht) had dropped from 0.57 (r ange 0.52-0.62) to 0.45 (0.34-0.49), Ena was stopped and, after a peri od of 3.8+/-0.3 months, Ht had risen again to baseline values (0.56, r ange 0.52-0.61) in 8 of them, These 8 patients were then given 5 mg/da y Ena. Ht decreased more slowly, and after 3 months reached a mean of 0.49 (0.44-0.54). Group 2 (9 patients) received 600 mg/day Thee in 2 d oses. After 2 months, Ht had decreased from 0.56 (0.52-0.61) to 0.52 ( 0.46-0.63), but in 5 patients, Ht remained above 0.51. After I month d iscontinuation of treatment, PTE persisted in 7 patients. These patien ts were given 10 mg/day Ena, whereupon Ht decreased from 0.55 (0.52-0. 64) to 0.46 (0.40-0.53) after 2 months and to 0.41 (0.33-0.47) after 3 months. Group 3 did not receive medical treatment, After 3 months, PT E persisted in 8 out of the 9 patients and remained unchanged during t he following 3 months. Mean values for Ht were: baseline, 0.55 (0.52-0 .58); after 3 months, 0.56 (0.53-0.59); and after 6 months, 0.55 (0.52 -0.60). We conclude that Ena is superior to Theo in the treatment of P TE, There were no resistant patients, but individual sensitivity diffe rs, Its effect is dose dependent, reversible, and reproducible, Excess ive Ht decrease may occur; thus, doses should be titrated individually .