Genetic Determinants of the Metabolism of Non-nucleoside Reverse Transcriptase Inhibitors

Inclusion Criteria: * Healthy African American men and women. * 18-55 years of age. * Willing and able to provide written informed consent. Exclusion Criteria: * Currently or recently (within the previous 30 days) received medications known or likely to be metabolized by, or interact wth the CYP450 enzymes. * Prior or current hepatic or psychiatric disease illness that in the judgment of the investigator would interfere in the study performance. * Active alcohol or illicit drug abuse use that in the judgment of the investigator would interfere in the study performance. * Alanine Aminotransferase (ALT) or Aspartate Aminotransferase (AST) \>1.5 X upper limit of normal. * Positive pregnancy test in women of childbearing potential.