Impact of once- and twice-daily dosing regimens on adherence and overall safety.

Low-frequency dosing regimens are the best options for long-term HAART with regard to convenience, adherence, and efficacy. In a drive to simplify HIV treatment, once-daily dosing has been advocated as more effective than twice-daily dosing at maintaining adherence and, therefore, controlling viral load. However, there are only a limited number of systematic studies comparing the safety and efficacy of such regimens. This review presents an overview of reduced-frequency dosing regimens from recent HAART trials and critically examines the factors related to adherence and therapeutic efficacy. Clinical data to guide individual treatment decisions are limited, and therapy--whether a once-daily, twice-daily, or other dosing schedule--should be selected based on individual patient needs.