The substantial benefits conferred by HAART require strict patient adherence. Many of the initial HAART regimens consisted of a number of large pills that needed to be taken several times daily, sometimes with meal restrictions. The development of once-daily antiretroviral agents has eased some of the burden associated with the intense, difficult schedules of early HAART regimens.. The majority of regimens currently used in treatment-naive HIV-positive patients contain a mixture of agents that are taken on a once- and twice-daily basis. Although this is an improvement over past regimens, the asynchronous administration of pills throughout the day still presents a scheduling challenge for most patients. The newest advance in simplifying antiretroviral therapy is the use of regimens in which all pills are taken at the same time once a day. Choosing drugs for a fully once-daily regimen requires awareness of a number of factors, including pharmacokinetics, potency, durability of response, resistance and safety. At this time, there are a limited number of combinations that can be used as a fully once-daily regimen and few clinical trials evaluating such combinations. Results from initial clinical trials using simplified, once-daily regimens in treatment-naive patients have been promising. Additional studies should add to this experience and provide guidance on the role and timing of such regimens in the management of patients with HIV disease.
