Can HIV infection be treated successfully with a once-daily regimen?

Although once-daily dosing might not be appropriate for all patients, this schedule provides patients with a regimen that can fit more easily into their established routines, thereby increasing treatment adherence. Maintaining strict adherence is especially important in the treatment of HIV infection, because drug-resistant variants of HIV can emerge in suboptimal treatment environments. Didanosine, tenofovir, efavirenz, and lamivudine are the 4 single-agent antiretroviral drugs currently approved for once-daily administration. The combination of amprenavir boosted with ritonavir was FDA-approved for once-daily use in February 2002. Other new antiretroviral drugs are currently in development, as are new dosing schedules for existing antiretroviral drugs. Combinations of antiretroviral drugs, especially protease inhibitors boosted with ritonavir, are also being studied.