Use progestin-dominant pills to treat pelvic pain
Cellular activity in endometriosis lesions is stimulated by estradiol and inhibited by a high concentration of androgenic progestins or androgens. This simplified endocrine paradigm explains the effectiveness of hormonal treatments that suppress ovarian estradiol production, including leuprolide, elagolix, medroxyprogesterone acetate, and NEA. For the woman in the above case, I would advocate for elagolix treatment but, following the insurance denial of the prescription, an alternative treatment for moderate or severe pelvic pain caused by endometriosis would be a progestin-dominant hormone medication (for example, NEA 5 mg daily). Norethindrone acetate 5 mg daily may be associated with bothersome adverse effects including weight gain (16% of patients; mean weight gain, 3.1 kg), acne (10%), mood lability (9%), hot flashes (8%), depression (6%), scalp hair loss (4%), headache (4%), nausea (3%), and deepening of the voice (1%).7
I sometimes see women with moderate to severe pelvic pain caused by endometriosis being treated with norethindrone 0.35 mg daily. This dose of norethindrone is suboptimal for pain treatment because it does not reliably suppress ovarian production of estradiol. In addition, the cells in endometriosis lesions are often resistant to the effects of progesterone, requiring higher dosages to produce secretory or decidual changes. In most situations, I recommend against the use of norethindrone 0.35 mg daily for the treatment of pelvic pain caused by endometriosis.
Patients commonly ask if NEA 5 mg daily has contraceptive efficacy. Although it is not approved at this dosage by the US Food and Drug Administration as a contraceptive,8 norethindrone 0.35 mg daily is approved as a progestin-only contraceptive.9 Norethindrone acetate is rapidly and completely deacetylated to norethindrone and the disposition of oral NEA is indistinguishable from that of norethindrone (which is the FDA-approved dosage mentioned above). Since norethindrone 0.35 mg daily is approved as a contraceptive, it is highly likely that NEA 5 mg daily has contraceptive efficacy, especially if there is good adherence with the daily medication.
CASE 3 Perimenopausal AUB
A 45-year-old woman reports varying menstrual cycle lengths from 24 to 60 days with very heavy menses in some cycles. Pelvic ultrasonography shows no abnormality. Endometrial biopsy shows a proliferative endometrium. Her serum progesterone level, obtained 1 week before the onset of menses, is < 3 ng/mL. She has no past history of heavy menses, easy bruising, excessive bleeding with procedures, or a family history of bleeding problems. She also reports occasional hot flashes that wake her from sleep.
Use an estrogen step-down regimen to manage postmenopause transition
This patient is likely in the perimenopause transition, and the abnormal uterine bleeding (AUB) is caused, in part, by oligo- or anovulation. Perimenopausal women with AUB may have cycles characterized by above normal ovarian estradiol production and below normal progesterone production, or frank anovulation.10 Elevated ovarian estrogen and low progesterone production sets the stage for heavy bleeding in the perimenopause, regardless of the presence of uterine pathology such as fibroids.
For perimenopausal women, one option for treatment of AUB due to anovulation is to prescribe an estrogen step-down regimen. For the 45-year-old woman in this case, initiating treatment with an E-P pill containing ethinyl estradiol 10 µg and NEA 1 mg will likely control the AUB and her occasional hot flash.11 As the woman ages, the ethinyl estradiol dose can be decreased to pills containing 5 µg and then 2.5 µg, covering the transition into postmenopause. Once the woman is in the postmenopause, treatment with transdermal estradiol and oral micronized progesterone is an option to treat menopausal vasomotor symptoms.
Optimize estrogen and progestin treatment for your patients
Many gynecologic problems are effectively treated by estrogen and/or progestin steroids. The dose of estrogen and progestin should be tailored to the specific problem. For PCOS, the estrogen dose selected should be sufficient to safely stimulate hepatic SHBG production. For endometriosis, if a GnRH antagonist is not available to the patient, a high-dose progestin, such as NEA 5 mg, may be an effective treatment. During the perimenopause transition in a woman with AUB, a treatment plan using a sequential E-P step-down program might control symptoms and help smoothly glide the patient into the postmenopause. ●