New kinetic data on estradiol in light of the vaginal ring concept

Safety of vaginal estrogens: a systematic review

OBJECTIVE

This systematic review included clinical trials of Food and Drug Administration-approved vaginal estrogens. The primary objective of this systematic review was to examine the comparative safety of the Food and Drug Administration-approved vaginal estrogen preparations among postmenopausal women.

METHODS

We performed a PubMed search of the primary literature from January 1, 1966 to July 16, 2019 for English-language clinical trials. Manual review of retrieved citations identified additional citations.

RESULTS

Of 882 retrieved citations, 75 clinical trials met inclusion criteria. Maximum trial duration was 52 weeks. None of the trials predesignated breast or endometrial cancer, cardiovascular events, or venous thromboembolism as primary outcomes. Studies were not designed to rule out an increase in endometrial carcinoma risk with long-term use of vaginal estrogen. There were few head-to-head comparisons. Fifty trials examined serum sex steroid and gonadotrophin levels; assay methodologies varied. Serum estradiol levels were 11 pg/mL at baseline or during placebo use and increased to a mean of 30 pg/mL after treatment. Estradiol levels were usually highest during the first 12 weeks of treatment, and were higher for estrogen creams than for inserts or rings. The 22 trials of endometrial thickness and the 15 trials of endometrial biopsy did not clearly demonstrate endometrial proliferation after vaginal estrogen treatment, but data were limited, and studies did not always perform systematic endometrial biopsy.

CONCLUSIONS

Newer low-dose estradiol rings, tablets, and inserts appear to induce the least increases in serum hormones, possibly indicating greater safety. Limited evidence in trials lasting up to 52 weeks suggest endometrial safety of vaginal estrogen use. Long-term trials are needed. : Video Summary:http://links.lww.com/MENO/A513.

Atrophic vaginitis

With the loss of estrogen that occurs with menopause, physiologic and structural changes occur within the vulvovaginal mucosa that lead to a condition commonly called atrophic vaginitis. Although mild genital changes occur in most women, 10-47% of postmenopausal women will develop one or more debilitating symptoms that include vulvovaginal dryness, dyspareunia, vulvar itching or pain, recurrent urinary tract infections, as well as abnormal vaginal discharge. Topical estrogen replacement therapies reverse these mucosal changes and are effective treatments for the symptoms of atrophic vaginitis. Vaginal moisturizers and lubricants also provide symptomatic relief for vaginal dryness and dyspareunia, respectively.

Challenges in the gynecologic care of premenopausal women with breast cancer

Premenopausal women with a new diagnosis of breast cancer are faced with many challenges. Providing health care for issues such as gynecologic comorbidities, reproductive health concerns, and vasomotor symptom control can be complicated because of the risks of hormone treatments and the adverse effects of adjuvant therapies. It is paramount that health care professionals understand and be knowledgeable about hormonal and nonhormonal treatments and their pharmacological parameters so they can offer appropriate care to women who have breast cancer, with the goal of improving quality of life. Articles for this review were identified by searching the PubMed database with no date limitations. The following search terms were used: abnormal uterine bleeding, physiologic sex steroids, endometrial ablation, hysteroscopic sterilization, fertility preservation in endometrial cancer, tranexamic acid and breast cancer, menorrhagia treatment and breast cancer, abnormal uterine bleeding and premenopausal breast cancer, levonorgestrel IUD and breast cancer, tamoxifen and gynecologic abnormalities, tamoxifen metabolism, hormones and breast cancer risk, contraception and breast cancer, pregnancy and breast cancer, and breast cancer and infertility treatment.

Women's health, breast health: a review of the gynecologic effects of breast cancer

Breast cancer is very common and seen in both premenopausal and postmenopausal women. Research into prevention, better screening, and more effective treatments is occurring continually, and changes are translated into clinical practice relatively quickly. It is important for women's health care providers to have an understanding of breast cancer treatments and the gynecologic side effects. For premenopausal women interested in fertility, options should be discussed prior to chemotherapy. Issues pertaining to pregnancy after breast cancer should be discussed in a multidisciplinary fashion, involving the obstetrician/gynecologist, breast surgeon, and oncologist. Ovarian suppression is often used as part of breast cancer treatment in premenopausal women with hormone positive disease, and menopausal symptoms may be severe. Hormonal therapies including tamoxifen and the aromatase inhibitors are used in the treatment of hormone positive breast cancers. Each of these drugs has a variety of gynecologic implications. Understanding the options for treatment for menopausal complaints in breast cancer patients is important for women's health providers. Although most breast cancers are sporadic, a small percentage will be due to mutations in the BRCA genes. It is important for women's health providers to take an appropriate family history and refer to genetic counselors for possible testing when hereditary cancer is suspected. This review focuses on the various women's health issues pertaining to breast cancer and treatment.

Menopause: evidence-based practice

Menopause is a physiologic transition and is assuming an increasing importance as the demographic bulge moves through this phase. The transition takes place over several years. It is characterized by depletion of the ovarian follicles, decreasing inhibin leading to increases in follicle-stimulating hormone and loss of the menstrual cycle, accompanied by decreased estradiol production and typical symptoms. The role of hormone therapy in menopause has shifted from preventive use to a limited role in symptom management, for which it remains the most effective intervention. There is good evidence from observational and randomized trials of an increased risk of breast cancer in women on estrogen plus a progestin, compared with those on estrogen alone. There are insufficient data to be able to determine if there are clinically important differences between various progestins and progesterone with respect to breast cancer risk, nor between different regimens. Even relatively short-term exposure to unopposed estrogen will increase the risk of atypical endometrial hyperplasia or cancer; women who have their uterus should be using a progestational agent. Lifestyle changes at menopause are important and effective for preventive health. Recent evidence suggests that the discordance between epidemiologic studies with respect to cardiovascular outcomes and the Women's Health Initiative randomized controlled trial (WHI RCT) data might be attributable in large part to the older age of women enrolled in the WHI.

Pharmacology of estrogens and progestogens: influence of different routes of administration

This review comprises the pharmacokinetics and pharmacodynamics of natural and synthetic estrogens and progestogens used in contraception and therapy, with special consideration of hormone replacement therapy. The paper describes the mechanisms of action, the relation between structure and hormonal activity, differences in hormonal pattern and potency, peculiarities in the properties of certain steroids, tissue-specific effects, and the metabolism of the available estrogens and progestogens. The influence of the route of administration on pharmacokinetics, hormonal activity and metabolism is presented, and the effects of oral and transdermal treatment with estrogens on tissues, clinical and serum parameters are compared. The effects of oral, transdermal (patch and gel), intranasal, sublingual, buccal, vaginal, subcutaneous and intramuscular administration of estrogens, as well as of oral, vaginal, transdermal, intranasal, buccal, intramuscular and intrauterine application of progestogens are discussed. The various types of progestogens, their receptor interaction, hormonal pattern and the hormonal activity of certain metabolites are described in detail. The structural formulae, serum concentrations, binding affinities to steroid receptors and serum binding globulins, and the relative potencies of the available estrogens and progestins are presented. Differences in the tissue-specific effects of the various compounds and regimens and their potential implications with the risks and benefits of hormone replacement therapy are discussed.

Effects of vaginally administered high estradiol doses on hormonal pharmacokinetics and hemostasis in postmenopausal women

OBJECTIVE

To study the effect of high doses of estradiol released from vaginal rings on the pharmacokinetics of hormones, and the long-term effect on hormones and hemostasis in postmenopausal women.

DESIGN

A pilot, nonrandomized study.

SETTING

Healthy volunteers in an academic research environment.

PATIENTS

Postmenopausal women. Eight women were treated with 17 beta-estradiol from three vaginal rings, releasing 7.5 micro g per ring for a total of 22.5 micro g over 24 hours. The rings were changed every morning for 14 days.

MAIN OUTCOME MEASURE(S)

Hemostatic changes were recorded.

RESULT(S)

Estradiol was rapidly absorbed, and statistically significant increases in the levels were found after 15 minutes; C(max) was obtained after 1 hour and a steady state after 24 hours. No statistically significant changes were found in the levels of coagulation factors V, von Willebrand factor, and activated factor VII; nor were any changes observed for activated protein C resistance, coagulation inhibitors protein C, protein S, or plasminogen activator inhibitor-1. No indication of increased thrombin formation was demonstrated by analyses of prothrombin fragment 1+2, fibrin D-dimer, and soluble fibrin. CONCLUSION(S)No statistically significant changes in hemostasis were observed from the vaginal administration of estradiol using a dose equivalent to transdermal administration with a release rate of 100 micro g per 24 hours.