Protease inhibitor-sparing HAART: A review of key studies

Some protease inhibitor (PI)-sparing regimens offer advantages over PI-based therapy for HIV infection, including more convenient dosing, lower tablet volume, fewer drug interactions, CNS penetration, and the option of using PIs as second-line therapy. There are no data comparing the 3 leading agents (efavirenz, nevirapine, abacavir), but comparisons between each agent and triple therapy using the PI indinavir exist. As initial therapy, nevirapine and abacavir seem on par with indinavir, and efavirenz may be superior. In addition, efavirenz regimens have outperformed indinavir regimens in high-viral-load patients. Finally, efavirenz has demonstrated superiority over the PI nelfinavir in nucleoside analogue-treated patients. Combining the 2 agents, however, appears to be best. Tolerability of these PI-sparing approaches is good. Most adverse events with efavirenz and nevirapine occur within the first month and can be managed without interrupting therapy. Adverse events with abacavir are uncommon except for a hypersensitivity reaction in 3% of recipients.