Effects of injectable contraception with depot medroxyprogesterone acetate or norethisterone enanthate on estradiol levels and menstrual, psychological and behavioral measures relevant to HIV risk: The WHICH randomized trial.

BACKGROUND: Observational data suggest lower HIV risk with norethisterone enanthate (NET-EN) than with depo-medroxyprogesterone acetate intramuscular (DMPA-IM) injectable contraceptives. If confirmed, a switch between these similar injectable methods would be programmatically feasible and could impact the trajectory of the HIV epidemic. We aimed in this paper to investigate the effects of DMPA-IM and NET-EN on estradiol levels, measures of depression and sexual activity and menstrual effects, relevant to HIV risk; and to ascertain whether these measures are associated with estradiol levels. METHODS: This open-label trial conducted at two sites in South Africa from 5 November 2018 to 30 November 2019, randomized HIV-negative women aged 18-40 to DMPA-IM 150 mg intramuscular 12-weekly (n = 262) or NET-EN 200 mg intramuscular 8-weekly (n = 259). Data were collected on hormonal, behavioral and menstrual effects at baseline and at 25 weeks (25W). RESULTS: At 25W, median 17ß estradiol levels were substantially lower than at baseline (p<0.001) for both methods: 76.5 pmol/L (interquartile range (IQR) 54.1 to 104.2) in the DMPA-IM group (n = 222), and 69.8 pmol/L (IQR: 55.1 to 89.3) in the NET-EN group (n = 225), with no statistical difference between the two methods (p = 0.450). Compared with DMPA-IM, NET-EN users reported significantly less amenorrhoea, fewer sexual acts, fewer users reporting at least one act of unprotected sex, more condom use with steady partner, more days with urge for sexual intercourse, more days feeling partner does not love her, and more days feeling sad for no reason. We did not find a clear association between estradiol levels and sexual behavior, depression and menstrual effects. Behavioral outcomes suggest less sexual exposure with NET-EN than DMPA-IM. The strength of this evidence is high due to the randomized study design and the consistency of results across the outcomes measured. CONCLUSIONS: Estradiol levels were reduced to postmenopausal levels by both methods. Secondary outcomes suggesting less sexual exposure with NET-EN are consistent with reported observational evidence of less HIV risk with NET-EN. A randomized trial powered for HIV acquisition is feasible and needed to answer this important question. TRIAL REGISTRATION: PACTR 202009758229976.

Misreporting contraceptive use and the association of peak study progestin levels with weight and BMI among women randomized to the progestin-only injectable contraceptives DMPA-IM and NET-EN.

Progestin-only injectable contraceptives, mainly depo-medroxyprogesterone acetate intramuscular (DMPA-IM), are the most widely used contraceptive methods in sub-Saharan Africa. Insufficient robust data on their relative side-effects and serum concentrations limit understanding of reported outcomes in contraception trials. The WHICH clinical trial randomized HIV-negative women to DMPA-IM (n = 262) or norethisterone enanthate (NET-EN) (n = 259) at two South African sites between 2018-2019. We measured serum concentrations of study and non-study progestins at initiation (D0) and peak serum levels, one week after the 24-week injection [25 weeks (25W)], (n = 435) and investigated associations between study progestin levels, and BMI and weight of participants. Peak median serum concentrations were 6.59 (IQR 4.80; 8.70) nM for medroxyprogesterone (MPA) (n = 161) and 13.6 (IQR 9.01; 19.0) nM for norethisterone (NET) (n = 155). MPA was the most commonly quantifiable non-study progestin at D0 in both arms (54%) and at 25W in the NET-EN arm (27%), followed by NET at D0 in both arms (29%) and at 25W in the DMPA-IM arm (19%). Levonorgestrel was quantifiable in both arms [D0 (6.9%); 25W (3.4%)], while other progestins were quantifiable in ≤ 14 participants. Significant negative time-varying associations were detected between MPA and NET concentrations and weight and BMI in both contraceptive arms and a significant increase was detected for peak serum progestin concentrations for normal weight versus obese women. Contraceptive-related reported outcomes are likely confounded by MPA, more so than NET, with reported DMPA-IM effects likely underestimated, at sites where DMPA-IM is widely used, due to misreporting of contraceptive use before and during trials, and 'tail' effects of DMPA-IM use more than six months before trial enrolment. Peak serum levels of MPA and NET are negatively associated with BMI and weight, suggesting another source of variability between trial outcomes and a potential increase in side-effects for normal weight versus overweight and obese women. Trail registration: The clinical trial was registered with the Pan African Clinical Trials Registry (PACTR 202009758229976).

Effects of norethindrone on the growth, behavior, and thyroid endocrine system of adult female western mosquitofish (Gambusia affinis).

Progestins are mainly used in pharmacotherapy and animal husbandry and have received increasing attention as they are widely detected in various aquatic ecosystems. In this study, adult female western mosquitofish (Gambusia affinis) were exposed to different concentrations of norethindrone (NET) (solvent control, 5.0 (L), 50.0 (M), and 500.0 (H) ng/L) for 42 days. Behaviors, morphological parameters, histology of the thyroid, thyroid hormone levels (TSH, T3, and T4), and transcriptional levels of nine genes in the hypothalamic-pituitary-thyroid (HPT) axis were examined. The results showed that NET decreased sociality but increased the anxiety of G. affinis. Sociality makes fish tend to cluster, and anxiety may cause G. affinis to reduce exploration of new environments. Female fish showed hyperplasia, hypertrophy, and glial depletion in their thyroid follicular epithelial cells after NET treatment. The plasma levels of TSH and T4 were significantly reduced, but T3 concentrations were significantly increased in the fish from the H group. In addition, the transcripts of genes (tshb, tshr, tg, dio1, dio2, thrb) in the brains of fish in the M and H treatments were significantly stimulated, while those of trh and pax2a were suppressed. Our results suggest that NET may impact key social behaviors in G. affinis and interfere with the entire thyroid endocrine system, probably via affecting the transcriptional expression of upstream regulators in the HPT axis.

Efficacy of estrogen-progestogen therapy for women with vascular retained products of conception following miscarriage or abortion.

OBJECTIVE: To assess the clinical characteristics and endocrinological background of women with vascular retained products of conception (RPOC) after miscarriage or abortion and evaluate the effect of estrogen-progestogen therapy (EPT) as an initial treatment on this population based on their endocrinological background. MATERIALS AND METHODS: Women with vascular RPOC after miscarriage or abortion at less than 20 weeks of pregnancy who were given EPT (conjugated estrogen and norethisterone) were retrospectively reviewed. Their clinical characteristics, hormonal parameters, ultrasonographic findings, and outcomes were evaluated. RESULTS: Of 35 women with vascular RPOC, 30 (86%) presented with vaginal bleeding at a visit, and 6 (17%) required inpatient management due to heavy bleeding. Among women who presented with vaginal bleeding, serum progesterone levels were significantly lower (0.25 vs. 6.5 ng/mL, p = 0.004) than those in women who did not present with vaginal bleeding. There were no differences in serum hCG levels (10.5 vs. 3.1 mIU/mL) or serum estradiol levels (65.4 vs. 162.3 pg/mL). After withdrawal bleeding following the first course of EPT, vaginal bleeding was stopped in 27 of the 30 women (90%), and 23 (66%) of all women had a thin and linear endometrium. All women could be treated by up to two courses of EPT and did not require additional interventions. The median duration to hCG normalization after the initial EPT was 24.5 (9-88) days. CONCLUSION: Women with vascular RPOC who have no bleeding had significantly higher levels of serum progesterone, indicating that administration of progestogen may have an effect on hemostasis. Endometrial bleeding can be prevented or stopped, and retained tissues can be conservatively expelled by oral administration of EPT, including norethisterone, in women with vascular RPOC.

Development and validation of an expanded panel of progestins using liquid chromatography-tandem triple quadrupole mass spectrometry to monitor protocol compliance in hormonal contraceptive pharmacokinetic/pharmacodynamic studies.

We developed and validated the use of ultra-high-performance liquid chromatography-heated electrospray ionization-tandem triple quadrupole mass spectrometry to simultaneously analyze serum concentrations of ethinylestradiol, dienogest, norelgestromin, norethindrone, gestodene, levonorgestrel, etonogestrel, segesterone acetate, medroxyprogesterone acetate, and drospirenone. The calibration range for all targets was 0.009-10 ng/mL, with lower limit of quantification of 0.009 ng/mL for all analytes except gestodene (0.019 ng/mL). We used our assay to check compliance among participants in a clinical trial, confirmed the use of drospirenone in 11 of 13 study participants, and evidence of noncompliant progestins in 2 (levonorgestrel = 1, norethindrone = 1). We conclude that this approach provides an accurate method to check protocol compliance in contraceptive clinical trials. IMPLICATIONS: The availability of a liquid chromatography-tandem triple quadrupole mass spectrometry multiprogestin analysis panel for simultaneous evaluation of the most common contraceptive steroids approved worldwide could improve monitoring of compliance and protocol adherence in clinical trials.

Norethindrone dosing for adequate menstrual suppression in adolescents.

OBJECTIVES: We sought to study factors predictive of achieving menstrual suppression with norethindrone vs. norethindrone acetate in adolescents, as optimal dosing is unknown. Secondary outcomes included analyzing prescriber practices and patient satisfaction. METHODS: We performed a retrospective chart review of adolescents ages <18 years presenting to an academic medical center from 2010 to 2022. Data collected included demographics, menstrual history, and norethindrone and norethindrone acetate use. Follow-up was measured at one, three, and 12 months. Main outcome measures were starting norethindrone 0.35 mg, continuing norethindrone 0.35 mg, achieving menstrual suppression, and patient satisfaction. Analysis included Chi-square and multivariate logistic regression. RESULTS: Of 262 adolescents initiating norethindrone or norethindrone acetate, 219 completed ≥1 follow-up. Providers less often started norethindrone 0.35 mg for patients with body mass index ≥25 kg/m2, prolonged bleeding, or younger age at menarche, but more often for patients who were younger, had migraines with aura, or were at risk of venous thromboembolism. Those with prolonged bleeding or older age at menarche were less likely to continue norethindrone 0.35 mg. Obesity, heavy menstrual bleeding, and younger age were negatively associated with achieving menstrual suppression. Patients with disabilities reported greater satisfaction. CONCLUSIONS: While younger patients more often received norethindrone 0.35 mg vs. norethindrone acetate, they were less likely to achieve menstrual suppression. Patients with obesity or heavy menstrual bleeding may achieve suppression with higher doses of norethindrone acetate. These results reveal opportunities to improve norethindrone and norethindrone acetate prescribing practices for adolescent menstrual suppression.

A Randomized Open-Label Study of Relugolix Alone or Relugolix Combination Therapy in Premenopausal Women.

BACKGROUND AND OBJECTIVE: Relugolix is a gonadotropin-releasing hormone receptor antagonist. Relugolix 40-mg monotherapy is associated with vasomotor symptoms and long-term bone mineral density loss due to hypoestrogenism. This study assessed whether the addition of estradiol (E2) 1 mg and norethindrone acetate (NETA) 0.5 mg to relugolix 40 mg (relugolix combination therapy) provides systemic E2 concentrations in the 20-50 pg/mL range to minimize these undesirable effects. METHODS: This was a randomized, open-label, parallel-group study to assess the pharmacokinetics, pharmacodynamics, safety, and tolerability of relugolix 40 mg alone or in combination with E2 1 mg and NETA 0.5 mg in healthy premenopausal women. Eligible women were randomized 1:1 to receive relugolix alone or relugolix plus E2/NETA for 6 weeks. Study assessments included pharmacokinetic parameters of E2, estrone, and relugolix in both treatment groups, and norethindrone in the relugolix plus E2/NETA treatment group at weeks 3 and 6. RESULTS: Median E2 24 h average concentrations with the relugolix plus E2/NETA group (N = 23) were 31.5 pg/mL, 26 pg/mL higher compared with the relugolix-alone group (6.2 pg/mL) (N = 25). There were 86.4% of participants in the relugolix plus E2/NETA group who had E2 average concentrations exceeding 20 pg/mL, the threshold expected to minimize bone mineral density loss, compared with 21.1% in the relugolix-alone group. Both treatments were generally safe and well tolerated. CONCLUSIONS: Relugolix 40 mg in combination with E2 1 mg and NETA 0.5 mg provided systemic E2 concentrations within a range expected to minimize the risk of undesirable effects of hypoestrogenism associated with the administration of relugolix alone. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov identifier no. NCT04978688. Trial registration date: 27 July, 2021; retrospectively registered.

Norethindrone suppress the germ cell development via androgen receptor resulting in male bias.

Progestins are widely used and detected in surface waters, and can affect gonad development and sexual differentiation in fish. However, the toxicological mechanisms of sexual differentiation induced by progestins are not well understood. Here, we investigated the effects of norethindrone (NET) and androgen receptor (AR) antagonist flutamide (FLU) on gonadal differentiation in zebrafish from 21 dpf (days post-fertilization) to 49 dpf. The results showed that NET caused male bias, while FLU resulted in female bias at 49 dpf. The NET and FLU mixtures significantly decreased the percentage of males compared to the NET single exposure. Molecular docking analysis showed that FLU and NET had similar docking pocket and docking posture with AR resulting in competitively forming the hydrogen bond with Thr334 of AR. These results suggested that binding to AR was the molecular initiating event of sex differentiation induced by NET. Moreover, NET strongly decreased transcription of biomarker genes (dnd1, ddx4, dazl, piwil1 and nanos1) involved in germ cell development, while FLU significantly increased transcription of these target genes. There was an increase in the number of juvenile oocytes, which was consistent with the female bias in the combined groups. The bliss independence model analysis further showed that NET and FLU had antagonistic effect on transcription and histology during gonadal differentiation. Thus, NET suppressed the germ cell development via AR, resulting in male bias. Understanding the molecular initiation of sex differentiation in progestins is essential to provide a comprehensive biological basis for ecological risk assessment.

In vitro chemo-preventive efficacy of synthetic progestin Norethindrone in human epithelial ovarian cancer.

Progestin-only based oral contraceptives are majorly used as 'minipill' to prevent unintended pregnancy and treat conditions like polycystic ovary syndrome, hirsutism, and acne. However, the dearth of literature has constrained our comprehension of the exogenous progestin in relation to ovarian cancer progression. Therefore, the aim of the present study was to evaluate the chemo-preventive potential of synthetic progestin Norethindrone (NET) in epithelial ovarian cancer in vitro. Briefly, SKOV3 cells were treated with 1, 10 and 100 µM concentrations of NET for seven days period. The assays for cell viability, wound-healing, cell cycle progression, detection of reactive oxygen species (ROS) and apoptosis were executed to illustrate the protective role of NET. To further clarify the underlying process, quantitative analysis of mRNA levels of oncogenes linked to angiogenesis, inflammation, proliferation, and metastasis (VEGF, HIF-1α, COX-2, and PGRMC1) and tumour suppressor (TP53) genes was conducted. Our study revealed that NET treatment significantly reduced SKOV3 cell growth by inducing cell cycle arrest at G2/M phase, elevating ROS levels, triggering cell death via apoptosis and necrosis, and inhibiting cell migration in a dose-dependent manner. Notably, NET also upregulated TP53 expression while concurrently downregulating VEGF, HIF-1α, COX-2, and PGRMC1 expression. Our results demonstrated that the chemo-preventive effect of Norethindrone may originate from the interaction of genes which exert a protective effect against ovarian carcinogenesis. The current findings also support further investigation, which may lead to changes in prescription practices or health-related advice for women.

Oral Gonadotropin-Releasing Hormone Antagonists for the Treatment of Uterine Leiomyomas.

Uterine leiomyomas are common hormone-responsive neoplasms that frequently cause heavy menstrual bleeding, anemia, pelvic pressure, pain, and adverse reproductive outcomes. In this overview, the efficacy and safety of oral gonadotropin-releasing hormone (GnRH) antagonists, co-administered with menopausal replacement-level steroid hormones or used at doses to avoid complete hypothalamic suppression, are reviewed for the management of uterine leiomyomas. Oral GnRH antagonists provide rapid suppression of sex steroids and avoid the initial steroidal flare and resultant temporary worsening of symptoms typically seen with parenteral GnRH agonists. Oral GnRH antagonists are effective in reducing leiomyoma-associated heavy menstrual bleeding, with high rates of amenorrhea and improved anemia and leiomyoma-associated pain, and providing modest reduction in uterine volume when used in combination with menopausal replacement-level steroid hormones. This add-back therapy can reduce hypogonadal side effects, including hot flushes and bone mineral density loss, close to levels seen with placebo therapy. Currently, both elagolix 300 mg twice daily with once-daily estradiol (1 mg) and norethindrone (0.5 mg) and relugolix 40 mg once daily with estradiol (1 mg) and norethindrone (0.5 mg) combination therapy are approved for leiomyoma treatment by the U.S. Food and Drug Administration. Linzagolix is under investigation in the United States but approved at two does with and without steroid hormones in the European Union. The efficacy of these agents appears to be robust over a wide spectrum of clinical presentations, demonstrating that worse disease parameters at baseline do not appear to inhibit efficacy. Across clinical trials, participants largely reflected the population of individuals affected by uterine leiomyomas.

Dienogest versus norethisterone acetate in management of endometrial hyperplasia without atypia.

OBJECTIVES: To compare the effectiveness of dienogest (DIE) and norethisterone acetate (NETA) regimens in the treatment of endometrial hyperplasia (EH) without atypia. METHODS: Participants were premenopausal women with irregular uterine bleeding, and endometrial hyperplasia without atypia on endometrial biopsy. Enrolled patients were randomly allocated into two groups: group I got DIE 2 mg/day (orally Visanne) for 14 days (10th to the 25th day of cycle) while group II received between the 16th and 25th day of the cycle, norethisterone acetate (NETA) 15 mg/d (orally Primolut Nor) was administered for 10 days. Both groups continued the therapy for six months. RESULTS: The DIE group showed a higher resolution (32.7%) and regression (57.7%) than NETA group (31% & 37.9%, respectively) with significant regression (p = 0.039). No progression in DIE group while four (6.9%) women in NETA group were recorded a progression to complex type without a significance. Also, NETA group showed a significant persistence rate (22.5%) than DIE group (3.8%) (p = 0.005). Also number in NETA group managed by hysterectomy with significant difference (p = 0.042). CONCLUSION: If used as first-line treatment, Dienogest produces a better rate of regression and a lower incidence of hysterectomy than Norethisterone Acetate does when used in EH without atypia.

Efficacy and safety of ultra-low-dose estradiol and norethisterone in postmenopausal Brazilian women.

OBJECTIVE: This study aimed to evaluate the efficacy and safety of oral ultra-low-dose continuous combination of 17ß-estradiol (17ß-E2) and norethisterone acetate (NETA) in postmenopausal Brazilian women. METHODS: Postmenopausal women (age 45-60 years) with amenorrhea >12 months and intact uterus, with moderate to severe vasomotor symptoms, were included. The vasomotor symptoms and endometrial bleeding were evaluated by a daily diary for 24 weeks, and the women were assessed at baseline and endpoint. RESULTS: A total of 118 women were included. The group treated with 0.5 mg 17ß-E2/0.1 mg NETA (n = 58) showed a percentage reduction of 77.1% in the frequency of vasomotor symptoms versus 49.9% in the placebo group (n = 60) (p = 0.0001). The severity score showed a reduction in the treatment group when compared to the placebo (p < 0.0001). The adverse events were comparable between the groups; however, in the 0.5 mg 17ß-E2/0.1 mg NETA group there were more complaints of vaginal bleeding; despite that, in most cycles in both treatment groups, more than 80% of women experienced amenorrhea. CONCLUSIONS: The combination of 0.5 mg 17ß-E2/0.1 mg NETA in a continuous combination regimen was shown to be effective in reducing the frequency and severity of vasomotor symptoms in Brazilian postmenopausal women.

Insights into the structure-function relationship of the NorQ/NorD chaperones from Paracoccus denitrificans reveal shared principles of interacting MoxR AAA+/VWA domain proteins.

BACKGROUND: NorQ, a member of the MoxR-class of AAA+ ATPases, and NorD, a protein containing a Von Willebrand Factor Type A (VWA) domain, are essential for non-heme iron (FeB) cofactor insertion into cytochrome c-dependent nitric oxide reductase (cNOR). cNOR catalyzes NO reduction, a key step of bacterial denitrification. This work aimed at elucidating the specific mechanism of NorQD-catalyzed FeB insertion, and the general mechanism of the MoxR/VWA interacting protein families. RESULTS: We show that NorQ-catalyzed ATP hydrolysis, an intact VWA domain in NorD, and specific surface carboxylates on cNOR are all features required for cNOR activation. Supported by BN-PAGE, low-resolution cryo-EM structures of NorQ and the NorQD complex show that NorQ forms a circular hexamer with a monomer of NorD binding both to the side and to the central pore of the NorQ ring. Guided by AlphaFold predictions, we assign the density that "plugs" the NorQ ring pore to the VWA domain of NorD with a protruding "finger" inserting through the pore and suggest this binding mode to be general for MoxR/VWA couples. CONCLUSIONS: Based on our results, we present a tentative model for the mechanism of NorQD-catalyzed cNOR remodeling and suggest many of its features to be applicable to the whole MoxR/VWA family.

Potential drug-drug interaction between warfarin and norethindrone in adolescent females: A case series.

PURPOSE: In the pediatric population, warfarin remains the recommended oral anticoagulant for valvular heart disease. Warfarin carries a risk of bleeding complications that can manifest as heavy menstrual bleeding (HMB) in postmenarchal adolescent females. As a result, these patients may be started on hormonal therapies, such as norethindrone, to suppress menstruation. SUMMARY: This case series describes a potential drug interaction between warfarin and norethindrone in 3 adolescent females with a history of mechanical mitral valve replacement who developed HMB. These patients were on stable warfarin regimens before the initiation of norethindrone and subsequently experienced increases in their international normalized ratio (INR). In response, they required an up to 50% reduction in their weekly warfarin dose over 5 to 12 weeks. CONCLUSION: These observations suggest that use of norethindrone for the management of HMB may significantly potentiate the anticoagulant effect of warfarin. Close INR monitoring and aggressive dose adjustments during initiation and discontinuation of norethindrone are recommended in patients on warfarin.

Short-term exposure to norethisterone affected swimming behavior and antioxidant enzyme activity of medaka larvae, and led to masculinization in the adult population.

Norethisterone (NET), one of the synthetic progestins, is detected with increasing frequency in the water environment and distributed in the ocean, with a potential toxicity risk to marine organisms. However, current studies on the adverse effects of progestins (including NET) in aquatic environments have focused on freshwater organisms, mainly fish. In the present, marine medaka (Oryzias melastigma) larvae were exposed to 91.31 ng/L NET for 10 days, and then the swimming behavior, oxidation-antioxidant-related enzyme activities, sex and thyroid hormone levels, and the gene transcription patterns of the larvae were measured. After NET treatment, medaka larvae were raised in artificial seawater until 5 months of age, and the sex ratio was counted. Ten-day exposure to 91.31 ng/L NET inhibited swimming behavior, of marine medaka larvae, which showed that the time in the resting state was significantly prolonged, while the time in the large motor state was significantly reduced; disrupted oxidative-antioxidant system, significantly up-regulated the enzymatic activities of reactive oxygen species (ROS), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px); affected the hormone levels of larvae, lowered 11- keto testosterone (11-KT) and triiodothyronine (T3) concentrations. RNA-seq results showed that 91.31 ng/L NET exposure for 10 days changed the transcript levels of 275 genes, of which 28 were up-regulated and 247 were down-regulated. Differentially expressed genes (DEGs) were mainly significantly enriched in piwi interacting RNA (piRNA), gonadal development, gametogenesis, and steroidogenesis biological processes, etc. After removing NET exposure and returning to breeding for 140 days, a significant increase in male proportions (69.67%) was observed in sexually mature medaka populations in the NET-treated group. These results show that exposure to 91.31 ng/L NET for 10 days can lead to various adverse effects on marine medaka larvae. These findings shed light on the potential ecological risks of synthetic progestins to marine organisms.

The effect of 17ß-estradiol plus norethisterone acetate treatment on lipoprotein (a), atherogenic and anti-atherogenic apolipoproteins levels in postmenopausal women: A meta-analysis of randomized controlled trials.

BACKGROUND AND AIM: The administration of 17ß-estradiol plus norethisterone acetate seems to confer women cardioprotection, however, its impact on lipoprotein (a) and apolipoproteins' concentrations remains unclear. Thus, we conducted a meta-analysis of randomized controlled trials (RCTs) to investigate the effect of 17ß-estradiol plus norethisterone acetate treatment on lipoprotein (a) and apolipoproteins' values in females. METHODS: We systematically searched four databases (PubMed/MEDLINE, Scopus, Embase, and Web of Science) to identify relevant publications published until March 9th, 2022. No language restrictions were applied. The random-effects model (the DerSimonian and Laird methods) was employed to calculate the weighted mean difference (WMD). RESULTS: The administration of 17ß-estradiol plus norethisterone acetate resulted in a significant decrease of lipoprotein (a) (WMD: -67.59 mg/L, 95 % CI: -106.39 to -28.80; P < 0.001) and apolipoprotein B concentrations (WMD: -3.71 mg/dL, 95 % CI: -6.68 to -0.75; P = 0.014), respectively. No effect of 17ß-estradiol plus norethisterone acetate on apolipoprotein AI (WMD: 0.23 mg/dL, 95 % CI: -3.99 to 4.46; P = 0.91) or AII (WMD: 0.21 mg/dL, 95 % CI: -2.24 to 2.68; P = 0.86) concentrations was detected. In the stratified analysis, there was a notable reduction in lipoprotein (a) levels in the RCTs with a duration of ≥6 months (WMD: -73.34 mg/L), in postmenopausal women with a BMI ≥25 kg/m2 (WMD: -69.85 mg/L) and in postmenopausal women aged ˂60 years (WMD: -61.93 mg/L). CONCLUSION: The present meta-analysis of RCTs demonstrates that 17ß-estradiol plus norethisterone acetate treatment reduces lipoprotein (a) and apolipoprotein B levels in postmenopausal women.

Fostemsavir and ethinyl estradiol drug interaction: Clinical recommendations for co-administration.

OBJECTIVES: Fostemsavir, a prodrug of temsavir, is indicated for heavily treatment-experienced adults with multidrug-resistant HIV-1 infection, antiretroviral (ARV) intolerance, or safety considerations. Understanding drug-drug interactions (DDIs) is important in individuals taking fostemsavir with hormonal contraceptives or menopausal or gender-affirming hormonal therapies. METHODS: Effect of temsavir (active moiety) on the pharmacokinetics of ethinyl estradiol (EE) and norethindrone (NET) was evaluated in an open-label, single-sequence, four-cycle, four-treatment study in 26 healthy female participants (study 206279, NCT02480881). Relevant ARV-contraceptive interaction studies and guideline recommendations were reviewed; that information was then applied to other contraceptive methods and hormone-based therapies to predict the impact of fostemsavir co-administration. RESULTS: Temsavir increased EE concentrations by 40% and had no effect on NET concentrations. Fostemsavir co-administration with hormone therapy is not expected to impact hormone treatment efficacy. Fostemsavir did not impact progestin; therefore, progestin-only and non-hormonal contraceptives will not be impacted by fostemsavir. Recommendations for co-administration of fostemsavir and hormonal contraceptives or menopausal or gender-affirming hormone therapies are based upon known and predicted DDIs, ensuring adequate hormonal concentrations to maintain the target effect. CONCLUSIONS: Applying the results of Study 206279 and other relevant ARV-contraceptive studies, we recommend that when co-administering fostemsavir with combined oral contraceptives (COCs) and other oestrogen-based therapies, EE dose should not exceed 30 µg or equivalent, and caution is advised in the case of individuals with risk factors for thromboembolic events. Other oestrogen-based therapies may be co-administered with fostemsavir, with monitoring of oestrogen concentrations and appropriate dose adjustments. No impact of fostemsavir on COC efficacy is expected.

Relugolix/Estradiol/Norethisterone (Norethindrone) Acetate: A Review in Symptomatic Uterine Fibroids.

An oral fixed-dose combination of relugolix/estradiol/norethisterone (also known as norethindrone) acetate (Ryeqo®; Myfembree®) has been approved for the management of heavy menstrual bleeding associated with uterine fibroids in the USA and management of moderate to severe symptoms of uterine fibroids in the EU. Relugolix is a gonadotropin releasing hormone (GnRH) receptor antagonist that decreases serum estradiol and progesterone concentrations to postmenopausal levels. The addition of estradiol/norethisterone acetate to relugolix ameliorates relugolix-induced bone loss and hot flush. In the two phase 3 LIBERTY trials, relugolix + estradiol/norethisterone substantially decreased menstrual bleeding and improved a range of other uterine fibroid symptoms in women with uterine fibroids-associated heavy menstrual bleeding. The combination was generally well tolerated, with vasomotor symptoms being the most common adverse reaction. Treatment with this combination for over up to 2 years did not induce a clinically meaningful bone loss in the majority of women. Relugolix/estradiol/norethisterone acetate, with its convenient once-daily administration, is a useful addition to current pharmacological treatment options for premenopausal women with symptomatic uterine fibroids.

Uterine fibroids are a common type of noncancerous tumours that grow in the uterus. In some women, these tumours cause debilitating symptoms, such as heavy menstrual bleeding, pelvic pain and passing of blood clots. Hysterectomy is the only definitive treatment for this condition, but is associated with some disadvantages. Less invasive procedures and medical treatments are now available to treat these symptoms. Recently, a fixed-dose tablet comprising relugolix, estradiol and norethisterone acetate (Ryeqo^®; Myfembree^®) has been approved to treat symptoms of uterine fibroids. This combination works by suppressing ovarian hormone levels. In clinical trials, relugolix + estradiol/norethisterone substantially reduced menstrual bleeding and improved several other symptoms in women with uterine fibroids-associated heavy menstrual bleeding. The combination was generally well tolerated and had a minimal impact on bone loss, a known adverse effect of such therapies. With its convenient once-daily administration, relugolix/estradiol/norethisterone acetate is a useful addition to current medical treatment options for premenopausal women with symptomatic uterine fibroids.

Upregulation of an estrogen receptor-regulated gene by first generation progestins requires both the progesterone receptor and estrogen receptor alpha.

Progestins, synthetic compounds designed to mimic the activity of natural progesterone (P4), are used globally in menopausal hormone therapy. Although the older progestins medroxyprogesterone acetate (MPA) and norethisterone (NET) have been implicated in increased breast cancer risk, little is known regarding newer progestins, and no significant risk has been associated with P4. Considering that breast cancer is the leading cause of mortality in women, establishing which progestins increase breast cancer incidence and elucidating the underlying mechanisms is a global priority. We showed for the first time that the newer-generation progestin drospirenone (DRSP) is the least potent progestin in terms of proliferation of the estrogen-responsive MCF-7 BUS breast cancer cell line, while NET and P4 have similar potencies to estradiol (E2), the known driver of breast cancer cell proliferation. Notably, MPA, the progestin most frequently associated with increased breast cancer risk, was significantly more potent than E2. While all the progestogens enhanced the anchorage-independent growth of the MCF-7 BUS cell line, MPA promoted a greater number of colonies than P4, NET or DRSP. None of the progestogens inhibited E2-induced proliferation and anchorage-independent growth. We also showed that under non-estrogenic conditions, MPA and NET, unlike P4 and DRSP, increased the expression of the estrogen receptor (ER) target gene, cathepsin D, via a mechanism requiring the co-recruitment of ERα and the progesterone receptor (PR) to the promoter region. In contrast, all progestogens promoted the association of the PR and ERα on the promoter of the PR target gene, MYC, thereby increasing its expression under non-estrogenic and estrogenic conditions. These results suggest that progestins differentially regulate the way the PR and ER converge to modulate the expression of PR and ER-regulated genes. Our novel findings indicating similarities and differences between P4 and the progestins, emphasize the importance of comparatively investigating effects of individual progestins rather than grouping them as a class. Further studies are required to underpin the clinical relevance of PR/ERα crosstalk in response to different progestins in both normal and malignant breast tissue, to either confirm or refute their suitability in combination therapy for ER-positive breast cancer.