Acute meningo-encephalitis on dose reduction of zidovudine.

In a study of treatment by zidovudine in 106 patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex, an acute meningo-encephalitic illness developed in 4 of 21 patients within 17 days after the dose of zidovudine had had to be reduced because of myelotoxicity. 3 of the 4 patients had previous clinical evidence of HIV encephalopathy. AIDS-related opportunist infection of the central nervous system was excluded. This acute meningo-encephalitic illness probably results from an increase in HIV replication following dose reduction.