Fail your first-line ritonavir-boosted protease inhibitor (PI) regimen? You may be better off staying the course than switching your HIV meds, provided you have little or no drug resistance. In a new analysis of 209 people in various clinical trials who experienced virologic failure while taking a PI along with two nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs, or nukes), just one person experienced a major PI-related drug mutation. (Failure was typically defined as a lack of a significant drop in viral load during the early treatment weeks or a viral load above 200 or 400 later on.) Two-thirds of the group kept taking the same drug regimen, and after 24 weeks they were just as likely to have a suppressed viral load as those who switched. Also, those who kept with the same meds had a lower rate of resistance to nukes—11 percent versus 30 percent—and an average of 275 CD4s, compared with 213 among those who switched.