Changing therapy in HIV.

Abstract

AIM: To review recent developments in research into HIV and antiretroviral therapy and how these developments have affected the monitoring and treatment of HIV infection. DEVELOPMENTS AND THEIR IMPLICATIONS: More antiretroviral agents of different types have become available over recent years; combination therapy with these agents is proving to be more effective than monotherapy with zidovudine. Viral load is now known to be a better predictor of clinical outcome than CD4+ cell counts, and, now that it can be measured reliably in plasma or serum, clinicians can make better-informed decisions about initiation and alteration of therapy. It has become possible (though only on a small scale) to determine genotypic and phenotypic sensitivity of patients' viral isolates so that assessments of drug resistance can be made and drug choices tailored accordingly. As more becomes known about beneficial and potentially harmful interactions between antiretroviral drugs and about cross-resistance, maximally effective combination therapy regimens that do not limit subsequent options can be chosen. CONCLUSIONS: These developments mean that combinations of antiretrovirals can be selected to provide effective (> 2 logs) and prolonged suppression of viral load. Effective combination therapies that do not limit further treatment options, initiated at the appropriate time, should increase the extent and duration of antiretroviral activity and hence clinical benefit to patients.