Combination antiretroviral therapy

Abstract

Several observations based on pathological and virological studies suggest that antiretroviral combination therapy can be a more appropriate tool than monotherapy to counteract HIV replication and its negative consequences. Within clinical trials, most of the evidence of this superiority is however based on the positive effects on surrogate markers. Recently, some important, clinical-endpoint based, phase III trials have been completed assessing the role of two-nucleoside treatment both in untreated and in AZT-treated subjects. The ACTG 155 study, although showing no overall benefit from changing to AZT + ddC after long-term AZT treatment, also suggested that this strategy could be effective in less advanced patients. The availability of new drugs with high antiviral activity in vivo, the new insights into the molecular bases of resistance and the possibility to measure the in vivo efficacy of drugs through viral quantification can now be used together to select more rationally effective combination regimens.