Introduction

Estrogen replacement therapy, with or without a progestin, has many indications and benefits; eg, it can help relieve symptoms of the climacteric (menopause), including hot flashes. It has a beneficial effect on bone, and helps prevent and treat osteoporosis. Unopposed estrogen replacement therapy may reduce atherosclerosis and coronary artery disease, but the addition of a progestin may actually increase the risk of coronary artery disease. Estrogen, given systemically or topically, effectively treats atrophic vaginitis, thus helping postmenopausal women maintain sexual function, and atrophic urethritis and the resulting incontinence. Some evidence suggests that estrogen may help prevent Alzheimer's disease. However, estrogen replacement therapy has some adverse effects and risks; it is therefore not suitable for all postmenopausal women.

Before estrogen replacement therapy is prescribed, a history and physical examination (eg, blood pressure, breast and pelvic examinations, a Papanicolaou test) are necessary, and the risks and benefits of the therapy should be fully discussed with the patient. Mammography should be performed (and repeated annually after age 50), because estrogen replacement therapy is contraindicated in patients with known or suspected breast cancer (see Table 120-1). An endometrial biopsy should be considered for patients who have a history of abnormal or heavy vaginal bleeding, who are at increased risk of preexisting endometrial hyperplasia, or who experience vaginal bleeding during estrogen and progestin replacement therapy at times other than immediately after withdrawal of progestin. Also, patients should have an annual endometrial biopsy if they are using unopposed estrogens, regardless of whether vaginal bleeding occurs. If adequate tissue cannot be obtained by biopsy, intraoperative dilatation and curettage (D & C) may be necessary.

In the USA, estrogen is usually combined with progesterone replacement therapy as cyclic treatment: For example, conjugated estrogens 0.625 mg are given daily, with medroxyprogesterone acetate 5 mg po given on days 1 through 13 each month. Another estrogen may be substituted for conjugated estrogens or another progestin for medroxyprogesterone acetate.

With this regimen, many patients have withdrawal bleeding between days 11 and 18. To avoid withdrawal bleeding, patients can use continuous rather than cyclic treatment; conjugated estrogens 0.625 or 1.25 mg as needed to control symptoms are given continuously with medroxyprogesterone acetate 2.5 mg/day. Irregular vaginal bleeding usually occurs for the first 3 months but usually stops. Medroxyprogesterone acetate 5 mg/day po may be needed if vaginal bleeding is persistent or if a higher dose of estrogen is necessary. If abdominal bloating and mastalgia occur, norethindrone 0.35 to 1.05 mg/day may be substituted for medroxyprogesterone acetate.