Oestrogen and cyclical progestogen in postmenopausal hormone replacement therapy.

Objective: To ascertain the effectiveness, safety and incidence of side effects of a postmenopausal hormone replacement regimen consisting of continuous conjugated equine oestrogens and cyclical medroxyprogesterone acetate given for the first 14 days of each calendar month.

Design: A six month, prospective, open label, two centre, outpatient study of continuous Premarin (0.625 mg; Wyeth-Ayerst) and cyclical Provera (10 mg; Upjohn). Dosage adjustment was allowed in one centre.

Study Population: Seventy-six postmenopausal women in Adelaide and Brisbane.

Main Outcome Measures: Menopausal symptom score, serum lipid levels, routine biochemical and haematological indices, endometrial histology and clinical bleeding pattern, blood pressure, weight changes, side effects, withdrawal from the study, compliance and necessary dose adjustment.

Main Results: Eight women withdrew from the study and nearly 50% experienced some minor side effect. Where dosage adjustment was allowed, almost all side effects were eliminated. Most patients had acceptable regular withdrawal bleeds although some were deemed heavy. There was a statistically highly significant 54% reduction in the menopausal symptoms score at three months and a 62% reduction at six months. Endometrial biopsy at six months showed atrophic or secretory endometrium with no inappropriate proliferation or hyperplasia. Total cholesterol and low density lipoprotein (LDL) cholesterol levels were significantly decreased. The high density lipoprotein (HDL) cholesterol level remained unchanged and triglyceride levels were raised within the normal range. There were no other clinically relevant biochemical, haematological or clinical changes.

Conclusion: Continuous conjugated equine oestrogens (0.625 mg) and cyclical medroxyprogesterone acetate (10 mg) for the first 14 days of each calendar month proved to be a safe and effective postmenopausal therapy regimen. Initial minor side effects were common but could be readily ameliorated with early follow-up and dose titration.