 The purpose of this study is to examine the interactions of buprenorphine-naloxone, a medication used to treat opiate heroin or prescription narcotic dependence, and medications used in the treatment of HIV disease including atazanavir Reyataz, fosamprenavir Lexiva, didanosine Videx, tenofovir Viread, atazanavir Reyatazritonavir Norvir, fosamprenavir Lexivaritonavir Norvir, lamivudine Epivir, or darunavir please note that we have completed drug interaction studies for buprenorphine with atazanavir, atazanavirritonavir, didanosine, tenofovir and lamivudine at the PIs previous university; for this CHR application only the studies needed to be completed at UCSFSFGH will be discussed or tuberculosisTB rifampin or rifabutin medications note: supplement application currently pending. Participants are those with opioid dependence who qualify for buprenorphinenaloxone treatment or they are healthy subjects without opioid dependence who participate in pharmacokinetics studies of the antiretroviral medications. A total of 160 such individuals will be enrolled in these studies please note that the studies have been ongoing at Virginia Commonwealth University for 3 years so that the total number of participants to be recruited at UCSFSFGH will be about 50 protocol completers. Participants take the HIV or tuberculosis medicines for up to 15 days depending on the medications administered and ability to schedule blood and urine sampling sessions. 