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 additio
nal risk of impairment, and this risk may be decreased as a result of antir
etroviral 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 ma
y result in impaired or more efficient drug clearance and, consequently, an
tiretroviral or substance abuse treatment failure. The clinical outcome of
this interaction may potentially include drug-related neurotoxicity or neur
ologic disease induced by HIV infection. The actual impact of these interac
tions on the occurrence of neurologic impairment and disease are unknown at
this time, and, therefore, require study.