The purpose of this study is to determine the effects of the antiretroviral drugs efavirenz and ritonavir on human brain LAAM disposition in vivo.

Inclusion

Each subject must meet all of the following criteria:

1. Male or non-pregnant female volunteer, 18-50 yr old
2. Good general health with no known major medical conditions
3. BMI < 33
4. Provide informed consent

Exclusion Criteria

Subjects will not be enrolled if any of the following criteria exist:

1. Known history of liver or kidney disease
2. History of major medical conditions
3. HIV seropositive
4. Fasting blood glucose > 110 mg/dl (because HAART can cause glucose intolerance)
5. Family history of type 2 diabetes
6. Use of prescription or non prescription medications, herbals or foods known to be metabolized by or altering P-glycoprotein or CYP3A (hormonal birth control medications are acceptable if alternative means of contraception are used)
7. Females who are pregnant or nursing
8. Females taking hormonal contraceptives who are unwilling to use alternative means of contraception
9. Contraindications to MRI (e.g., metal implants or splinters in the body; a worn or implanted medical device, such as a pacemaker or drug pump; inability to lie flat for up to one hour; claustrophobia) or contraindications to PET scanning (e.g., inability to lie flat for up to one hour, claustrophobia, current
10. Current or recent (within 12 months prior to screening) participation in research studies involving radiation exposure such that the total research-related radiation dose to the subject in any given year would exceed the limits set forth in the US Code of Federal Regulations (CFR) Title 21 Section 361.1 (http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?FR=361.1))