Please tell me if protease inhibitors and birth control pills such as Loestrin can be used at the same time without diminishing effectiveness of either. Some doctors I have spoken to indicate that p.i. diminish birth control pills' effectiveness.

Some protease inhibitors can effect the metabolism of birth control pills and summary tables of the effects and recommendations can be seen in "Guidelines for the Use of Antiretrovirals in HIV-Infected Adults and Adolescents" (available on this web site). Generally, there do not appear to be any interactions between indinavir and birth control pills. Protease inhibitors with potential interactions include ritonavir, nelfinavir, and possibly amprenavir -- use of additional or alternative methods of birth control are recommended with these agents.

Katherine Luzuriaga, M.D.