- Have received certain antiretroviral (anti-HIV) drugs or are taking certain medications. (This study has been changed to increase enrollment. The eligibility criterion in earlier versions was more restrictive, and has been changed to include women receiving SQV [with or without RTV], 3TC, and ZDV for longer than 3 weeks if their pre-entry viral load is 400 copies/ml or less OR if they have a significant reduction in viral load within 90 days of the pre-entry visit.)