INTERMITTENT ZIDOVUDINE REGIMEN IN PATIENTS WITH SYMPTOMATIC HIV-INFECTION AND PREVIOUS HEMATOLOGICAL TOXICITY

Thirteen patients with AIDS or ARC on continuous zidovudine therapy (8 00-1200 mg daily), who developed severe anaemia (median Hb 7.9 g dl-1 range 4.9-9.4) after 66 days of treatment (median, range 35-258) were then treated with an intermittent regimen in an open study. The regime n consisted of cycles of 4 weeks on treatment (600-100 mg daily) follo wed by 2 weeks off. Intermittent treatment was tolerated for a signifi cantly longer period of time (median 257 days range 72-603) and a high er cumulative does (P < 0.001). Four patients discontinued intermitten t therapy in the period of follow-up, three due to bone marrow suppres sion. Eight of 13 patients needed red cell transfusions on continuous therapy compared to only one on the intermittent regimen. On intermitt ent therapy median haemoglobin concentration and neutrophil counts rem ained stable (Hb median 11.9 g dl-1 range 9.1-14.8, neut. median 1.7 x 10(9) l-1 range 0.6-4.3). Ten patients had detectable levels of P24 a ntigen which decreased from a median of 128 pg ml-1 (range 15-242) to 24 pg ml-1 (range 0-53) on continuous therapy. Subsequently, in eight of these patients on the intermittent regimen, levels of P24 Ag remain ed below 50% of initial pretreatment values (median 28 pg ml-1 range 0 -178) or below 50 pg ml-1.