Darunavir and Rilpivirine Interactions With Etonogestrel Contraceptive Implant

Inclusion Criteria: 1. Evidence of a personally signed and dated informed consent document indicating that the participant has been informed of all pertinent aspects of the study. 2. Participants who are willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures. 3. Women age 18 years to 45 years 4. Diagnosed with HIV infection 5. Medically eligible for the ENG subdermal implant as a contraceptive method based on the WHO Medical Eligibility Criteria for Contraceptive Use 6. Receiving EFV- or LPV/r-based ART for a minimum of 1 year 7. If not abstinent, must agree to use an effective non-hormonal method of contraception for the duration of the study including male and female condoms or the copper-T intrauterine device. 8. Participants must have a negative urine pregnancy test at entry and report no unprotected sex since the last menstrual period or in the last two weeks. \- Exclusion Criteria: 1. HIV RNA greater than 50 copies/mL at the screening visit 2. CD4 count below 200 cells/mm3 at the screening visit 3. History of virologic failure on the current regimen (two consecutive viral load results equal to or greater than 400 copies/mL) 4. Serum hemoglobin less than 9.0 g/dl at screening 5. Elevations in serum levels of alanine transaminase (ALT) above 5 times the upper limit of normal 6. Elevations in serum creatinine above 2.5 times the upper limit of normal 7. Use of drugs known to be contraindicated with ENG, RPV (for women taking EFV-based ART), or DRV (for women taking LPV-based ART) within 30 days of study entry. Due to the dynamic nature of drug interactions related to antiretroviral therapy, the study team will review all concomitant medications at screening based on the US Department of Health and Human Services drug interaction table and the University of Liverpool HIV drug interaction tables (www.hiv-druginteractions.org) 8. Currently pregnant or postpartum \<30 days at study entry. 9. Breastfeeding women within 6 months of delivery. 10. Patients with a history of hypersensitivity to ENG implant, undiagnosed vaginal bleeding, diagnosed or suspected sex hormone dependent neoplasia, benign or malignant liver tumor, or thromboembolic disease. 11. Presence of any active clinically significant disease or life-threatening disease that, in the investigator's opinion, would compromise the subject's safety or outcome of the study. \-