KETANSERIN - A NEW PERSPECTIVE IN POSTTRANSPLANT ERYTHROCYTOSIS

We have recently shown that ketanserin, an antagonist of peripheral se rotonin 5-HT2 receptors lowers blood erythropoietin (Epo) levels in so me chronic hemodialysis patients. Based on this finding, a preliminary study was undertaken to investigate the effect of a 3-week oral ketan serin administration on serum Epo concentration and relevant hematolog ical parameters in 4 renal allograft recipients with posttransplant er ythrocytosis (PTE). We found a marked decrease in Epo concentrations f ollowing ketanserin administration, from 48% to 76% of the abnormally elevated pretreatment values with subsequent increases at 3 weeks afte r discontinuation of the drug in all patients studied. In 3 of them a corresponding decrease or no rise in the erythrocyte count were noted. During the 6-week study period, the need for monthly phlebotomies was eliminated in these patients. It is hypothesized that ketanserin dimi nishes erythropoietin synthesis and may become a new drug in the treat ment of posttransplant erythrocytosis.