There are dozens of medications containing combinations of estrogen and progestin. I am often confused by the bewildering proliferation of generic brand names used to describe the same estrogen-progestin (E-P) regimen. For example, the combination medication containing ethinyl estradiol 20 µg plus norethindrone acetate (NEA) 1 mg is available under at least 5 different names: Lo Estrin 1/20 (Warner Chilcot), Junel 1/20 (Teva Pharmaceuticals), Microgestin Fe 1/20 (Mayne Pharma), Gildess 1/20 (Qualitest Pharmaceuticals), and Larin 1/20 (Novast Laboratories). To reduce the confusion, it is often useful to select a single preferred estrogen and progestin and use the dose combinations that are available to treat a wide range of gynecology problems (TABLE). In this editorial I focus on using various dose combinations of ethinyl estradiol and NEA to treat 3 common gynecologic problems.
CASE 1 Polycystic ovary syndrome
A 19-year-old woman reports 4 spontaneous menses in the past year and bothersome facial hair and acne. Her total testosterone concentration is at the upper limit of normal (0.46 ng/mL) and her sex hormone binding globulin (SHBG) concentration is at the lower limit of normal (35 nM). For treatment of the patient’s menstrual disorder, what is an optimal E-P combination?
Prioritize the use of an estrogen-dominant medication
Based on the Rotterdam criteria this woman has polycystic ovary syndrome (PCOS).1 In women with PCOS, luteinizing hormone (LH) secretion is increased, stimulating excessive ovarian production of testosterone.2 In addition, many women with PCOS have decreased hepatic secretion of SHBG, a binding protein that prevents testosterone from entering cells, resulting in excessive bioavailable testosterone.3 The Endocrine Society recommends that women with PCOS who have menstrual dysfunction or hirsutism be treated initially with a combination E-P hormone medication.1 Combination E-P medications suppress pituitary secretion of LH, thereby reducing ovarian production of testosterone, and ethinyl estradiol increases hepatic secretion of SHBG, reducing bioavailable testosterone. These two goals are best accomplished with an oral E-P hormone medication containing ethinyl estradiol doses of 20 µg to 30 µg per pill. An E-P hormone medication containing pills with an ethinyl estradiol dose ≤ 10 µg-daily may stimulate less hepatic production of SHBG than a pill with an ethinyl estradiol dose of 20 µg or 30 µg daily.4,5 In addition, E-P pills containing levonorgestrel suppress SHBG hormone secretion compared with E-P pills with other progestins.6 Therefore, levonorgestrel-containing E-P pills should not be prioritized for use in women with PCOS because the estrogen-induced increase in SHBG will be blunted by levonorgestrel.
CASE 2 Moderate to severe pelvic pain caused by endometriosis
A 25-year-old woman (G0) with severe dysmenorrhea had a laparoscopy showing endometriosis lesions in the cul-de-sac and a peritoneal window near the left uterosacral ligament. Biopsy showed endometriosis. Postoperatively, the patient was treated with an E-P pill containing 30 µg ethinyl estradiol and 0.15 mg desogestrel per pill using a continuous-dosing protocol. During the year following the laparoscopy, her pelvic pain symptoms gradually increased until they became severe, preventing her from performing daily activities on multiple days per month. She was prescribed elagolix but her insurance did not approve the treatment. What alternative treatment would you prescribe?
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