The study is a 14-day study with a 21-day follow-up period. During the 14-days of active study period, participants will receive Racivir once daily in combination with efavirenz and stavudine. Following the administration of the first and last dose of study medication, patients will remain in the clinic overnight. During the study there will be medical and medication histories taken, physical examinations, vital sign measurements, EKGs, and routine clinical laboratory tests.