Efficacy and safety of 17alpha-hydroxyprogesterone caproate in hormone replacement therapy.

The aim of the present study was to evaluate the efficacy (in terms of induction of uterine bleeding) and safety (in terms of absence of endometrial hyperplasia) of 17alpha-hydroxyprogesterone caproate (17alpha-HPC) in a therapeutic regimen for hormonal replacement after menopause. Fifty postmenopausal patients received hormone replacement therapy (HRT) for 24 weeks. The treatment regimen consisted of standard estrogen replacement therapy at commonly prescribed doses for the prevention of climacteric symptoms and 341 mg of 17alpha-HPC every 30 days. Enrolled women were told to expect withdrawal bleeding 7-10 days after the administration of 17alpha-HPC. Forty-eight patients completed the trial. In 91.7% of cases, patients experienced the expected pattern, i.e., strict withdrawal bleeding exclusive of any other form of bleeding. Breakthrough bleeding and/or other forms of abnormal bleeding affected only four women. At the 6th month none of the endometrial samplings motivated by endometrial thickness >10 mm and evidence of heterogeneous echogenicity (two cases) was positive for carcinoma. No biopsies had to be performed at the end of the 12th month of treatment. No serious adverse effect where recorded during the study period. In conclusion, our data show the efficacy and safety of 17alpha-HPC in HRT.