STUDY OF THE ROLE OF VITAMIN-B-12 AND FOLINIC ACID SUPPLEMENTATION INPREVENTING HEMATOLOGIC TOXICITY OF ZIDOVUDINE

A prospective, randomized study was conducted to evaluate the role of vitamin B-12 and folinic acid supplementation in preventing zidovudine (ZDV)-induced bone marrow suppression. Seventy-five human immunodefic iency virus (HIV)-infected patients with CD4+ cell counts (500/mm(3) w ere randomized to receive either ZDV (500 mg daily) alone (group I, n = 38) or in combination with folinic acid (15 mg daily) and intramascu lar vitamin B-12 (1000 mu g monthly) (group II, n = 37). Finally, 15 p atients were excluded from the study (noncompliance 14, death 1); thus , 60 patients (31 in group I and 29 in group II) were eligible for ana lysis. No significant differences between groups were found at enrollm ent. During the study, vitamin B-12 and folate levels were significant ly higher in group II patients; however, no differences in hemoglobin, hematocrit, mean corpuscular volume, and white-cell, neutrophil and p latelet counts were observed between groups at 3, 6, 9 and 12 months. Severe hematologic toxicity (neutrophil count < 1000/mm(3) and/or hemo globin < 8 g/dl) occurred in 4 patients assigned to group I and 7 assi gned to group II. There was no correlation between vitamin B-12 or fol ate levels and development of myelosuppression. Vitamin B-12 and folin ic acid supplementation of ZDV therapy does not seem useful in prevent ing or reducing ZDV-induced myelotoxicity in the overall treated popul ation, although a beneficial effect in certain subgroups of patients c annot be excluded.