 - After four doses of indinavir: About a week after taking the midazolam, participants will take 800 mg of indinavir two capsules 3 times a day every 8 hours for 1 day. The following morning they will come to the clinic, where a catheter flexible plastic tube will be placed in an arm vein for repeated blood draws. A blood sample will be drawn, and a fourth and final dose of indinavir will be given. Seven blood samples of about a teaspoon each will then be collected through the catheter over an 8-hour period to measure blood levels of the drug. 