HIGH-DOSE ZIDOVUDINE INDUCTION IN HTLV-I-ASSOCIATED MYELOPATHY - SAFETY AND POSSIBLE EFFICACY

Ten HTLV-I-associated myelopathy (HAM) patients (four men and six wome n aged 38 to 58 years) with Expanded Disability Status Scale (EDSS) sc ores ranging from 4.0 to 8.5 entered an open-label zidovudine study. A high-dosage induction (2 g/d for 4 weeks) was followed by 1 g/d for 2 0 weeks. Five patients were natives of the Caribbean island Hispaniola , and one each was from Colombia, Cuba, El Salvador, Jamaica, and the United States; all were positive by polymerase chain reaction, and nin e had positive Western immunoblots for HTLV-I. Side effects included a nxiety, insomnia, gastric upset, anorexia, and loss of taste. Preexist ing leg cramps were increased in two and headaches in one. Hemoglobin decreased from a mean of 13.5 to 11.8 g/dl and the hematocrit from 40. 7% to 34.9% at 8 weeks, and then stabilized. Neutropenia appeared regu larly but did not necessitate drug withdrawal. Mean EDSS scores change d little for the group as a whole, but the seven ambulatory patients i mproved objectively, with their scores dropping from 5.5 to 4.0 and no ne worsening. Timed gait improved by at least 50%. Following withdrawa l, four of the five who had improved regressed. Zidovudine appears to be safe in subjects with HAM who have no other major health problems a nd should be investigated further.