Inclusion Criteria

Patients may be eligible for this study if they:

• Are postmenopausal women over 18 years old.
• Are infected with HIV.
• Have a CD4 cell count of 100 cells/mm3 or greater within 45 days prior to study entry.
• Have a plasma viral load less than 55,000 copies/ml within 45 days prior to study entry.
• Are willing to comply with study requirements. These include not changing smoking habits during the course of the study and not consuming caffeine or alcohol prior to PK sampling.
• Have had a Pap smear within 12 months prior to study entry.
• Meet one of the following requirements: a) patients must currently be on stable PI or EFV regimens plus 2 or more acceptable NRTIs, or b) patients must not currently be taking any ARVs, with the exception of an NRTI-only regimen.
• Have a way to obtain their ARVs outside of the study and agree to continue their ARV regimen for at least 12 weeks of the study.

Exclusion Criteria

Patients may not be eligible for this study if they:

• Have had breast or endometrial cancer, thrombophlebitis, or thromboembolism.
• Have had serious nausea, vomiting, or abdominal pain within 30 days prior to study entry.
• Have had a serious illness requiring systemic treatment and/or hospitalization within 14 days prior to study entry.
• Are allergic or sensitive to the drugs that will be used for HRT.
• Have undiagnosed postmenopausal bleeding.
• Have coronary artery disease.
• Have used hormonal therapies within 8 weeks prior to study entry.
• Have used DMPA (Depo Provera) within 180 days prior to study entry.
• Have used the anti-HIV drugs ZDV and d4T at the same time within 30 days prior to study entry.
• Have used other medications specified in the protocol within 30 days prior to study entry.
• Are using experimental drugs without the written approval of the study co-chairs.
• Are unable to adhere to the ARV or HRT medications while on study, in the opinion of the investigator.