It is important to determine which medications for HIV-associated diseases, such as Mycobacterium avium complex (MAC) disease, can be given safely and effectively with anti-HIV drugs. Indinavir and rifabutin have been given simultaneously in the past with good results. This study seeks to examine if staggering the doses will make the 2 drugs more effective. HIV-negative volunteers are used in this study to examine the effect of rifabutin on indinavir and the effect of staggered rifabutin doses. The effect of rifabutin on the drug activity of indinavir is evaluated in HIV-positive patients.