Neurologic disease in injection drug users: therapeutic issues.

Illicit drug use may cause nervous system impairment as a result of direct and indirect effects on the integrity and function of nervous system tissue and, potentially, through immune effects. HIV-1 infection poses an additional risk of impairment, and this risk may be decreased as a result of antiretroviral drug treatment. Obviously, the goal of such therapy is to improve the potential clinical course of infection. However, interactions between antiretroviral drugs, abused drugs, and hepatic metabolic enzyme systems may result in impaired or more efficient drug clearance and, consequently, antiretroviral or substance abuse treatment failure. The clinical outcome of this interaction may potentially include drug-related neurotoxicity or neurologic disease induced by HIV infection. The actual impact of these interactions on the occurrence of neurologic impairment and disease are unknown at this time, and, therefore, require study.