Multiple ways that drug abuse might influence AIDS progression: clues from a monkey model.

Whether opiates and other drugs of abuse affect AIDS progression has been an unresolved issue for two decades. Credible evidence has suggested that opiates may exacerbate, retard or have 'no effect' on progression of AIDS. Differences may exist in AIDS-progression outcomes after opiate exposures that relate to neural versus, strictly, somatic AIDS; but it is also likely that conditional variables inherent to drug dependency and the nature of the infectious agents involved allow for differing outcomes. Data from epidemiological studies, and from in vitro and basic immunological studies regarding opiate effects on AIDS progression must be interpreted in light of the conditionality of opiate effects. Caution is sounded, also, about interpreting common depressive immunological effects of opiates as indicators of influence over AIDS progression. Current evidence from the monkey model of AIDS indicates that opiates can, under certain defined conditions, retard AIDS progression. The clinical relevance of these data remains to be defined. Importantly, such data imply that opioids and the endogenous opioid system may represent therapeutic tools and targets for altering AIDS progression.