Management of HIV infection in adults

The natural history of HIV infection continues to change with improved diagnostic and therapeutic modalities available to manage opportunistic infections and malignancies. Antiretroviral therapy with zidovudine and other investigational agents has improved the median survival of AIDS patients from 11 months in 1985 to 18-25 months at present. Most importantly, early intervention with zidovudine can delay onset of clinical illness in asymptomatic patients and progression to AIDS in symptomatic patients. A 500 mg/d dose has been found as effective as previously recommended doses of 1200-1500 mg/day. Lower doses decrease the incidence and severity of adverse effects and therapeutic benefit appears to be greatest in asymptomatic patients with CD4 lymphocyte counts less than 500/ul. Indications for zidovudine, therefore, have been expanded to include asymptomatic adults with CD4 lymphocyte counts less than 500/ul. Concerning early intervention with zidovudine, studies were not designed to measure survival or define the optimal timing of intervention based on immunologic status. In addition, long-term benefits are not clearly defined, particularly since the drug seems to lose clinical effectiveness after approximately two years, probably due to emergence of resistant HIV strains. Adverse effects continue to occur even at low doses including headaches, nausea, anemia and neutropenia, myopathy and possible hepatitis. Nevertheless, the overall clinical benefit seems to be greatest, albeit temporary, in asymptomatic patients. The optimal dosage appears to be 500-600 mg/d; however, this may not be sufficient for infection in the central nervous system.