This will be a non-randomized, cohort study. 8 patients in each of 3 weight ranges (< 160lb, 161-200lb, > 200lb) will be recruited to participate in the study. Subjects will be HIV + patients currently on stable therapy with nevirapine (on medication for at least 3 months with minimal self-reported adherence) as part of a combination regimen for their Human Immunodeficiency Virus (HIV) infection (as prescribed by their primary care provider). Subjects are to be in good health with liver function tests will be < 2 times normal limits, measured within 1 month prior to the study period. All subjects will be male. The reasoning for this gender bias is as follows: if both genders are to be used, there should be an equal number of male and female subjects to remove any bias from the data. Since there are not enough females taking nevirapine to be able to appropriately recruit, females will be excluded.