Femring

— THERAPEUTIC CATEGORIES —
  • Menopause and HRT

Femring Generic Name & Formulations

General Description

Estradiol acetate 0.05mg/day, 0.1mg/day; vaginal ring.

Pharmacological Class

Estrogen.

How Supplied

Ring—1

Storage

Store at 20º C to 25º C (68º F to77º F); excursions permitted to -20º C to 40º C (-4º F to 104º F). Do not store unpouched.

Manufacturer

Generic Availability

NO

Mechanism of Action

Endogenous estrogens are largely responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Estrogens act through binding to nuclear receptors in estrogen-responsive tissues. Circulating estrogens modulate the pituitary secretion of the gonadotropins, luteinizing hormone (LH) and FSH through a negative feedback mechanism. Estrogens act to reduce the elevated levels of these hormones seen in postmenopausal women.

Femring Indications

Indications

Moderate to severe vasomotor symptoms of menopause. Moderate to severe vulvar and vaginal atrophy due to menopause.

Femring Dosage and Administration

Adult

Use lowest effective dose for shortest duration consistent with treatment goals. Insert 1 ring vaginally once every 3 months; replace. Initially 0.05mg/day ring; may increase to 0.1mg/day ring if needed.

Children

Not applicable.

Femring Contraindications

Contraindications

Undiagnosed abnormal genital bleeding. Breast or other estrogen-dependent neoplasms. Active DVT, PE, or history of. Active arterial thromboembolic disease (eg, stroke, MI) or a history of. Hepatic impairment or disease. Protein C, protein S, or antithrombin deficiency, or other thrombophilias. Pregnancy.

Femring Boxed Warnings

Boxed Warning

Endometrial cancer. Breast cancer. Cardiovascular disorders. Probable dementia.

Femring Warnings/Precautions

Warnings/Precautions

Increased risk of endometrial carcinoma or hyperplasia in women with intact uterus (adding progestin is essential). Not for prevention of cardiovascular disease or dementia. Increased risk of cardiovascular events (eg, MI, stroke, VTE); discontinue if these occur or are suspected. Manage risk factors for cardiovascular disease and venous thromboembolism appropriately. Discontinue at least 4–6 weeks before surgery type associated with increased risk of thromboembolism or during prolonged immobilization. Increased risk of breast or ovarian cancer. Risk of probable dementia in women >65yrs of age. Gallbladder disease. Severe hypercalcemia in breast cancer or bone metastases. Visual abnormalities. Permanently discontinue if papilledema or retinal vascular lesions reveals on exam. Preexisting hypertriglyceridemia. History of cholestatic jaundice. Discontinue if pancreatitis, hypercalcemia, or recurrence of cholestatic jaundice occurs. Monitor thyroid function. Monitor conditions that may predispose to fluid retention. Hypoparathyroidism. Endometriosis. Hereditary angioedema. Asthma. Diabetes. Epilepsy. Migraine. Porphyria. SLE. Hepatic hemangiomas. Narrow vagina, vaginal stenosis, vaginal infections, cervical prolapse, rectoceles and cystoceles increase risk of irritation or ulceration. May use ring while treating vaginal infections. Do initial complete physical and repeat yearly (include Pap smear, mammogram, BP). Reevaluate periodically. Nursing mothers: not recommended.

Femring Pharmacokinetics

Absorption

Mean time to maximum concentration: ~1 hour (range: 0.25–1.5 hours). Average serum estradiol concentration: 40.6 pg/mL after administration of Femring (0.05mg/day estradiol); 76 pg/mL after administration of Femring (0.10 mg/day estradiol).

Distribution

Estrogens are widely distributed in the body and are generally found in higher concentrations in the sex hormone target organs. Estrogens circulate in the blood largely bound to SHBG and albumin.

Metabolism

Hepatic.

Elimination

Renal. Half-life: 21–26 hours.

Femring Interactions

Interactions

May be potentiated by CYP3A4 inhibitors (eg, erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir, grapefruit juice). May be antagonized CYP3A4 inducers (eg, phenobarbital, carbamazepine, rifampin, St. John's wort). Concomitant thyroid replacement; may need to increase thyroid dose. May interfere with lab tests (eg, thyroid, PT, coagulation factors, glucose tolerance, HDL/LDL, triglycerides, hormone concentrations, other binding or plasma proteins).

Femring Adverse Reactions

Adverse Reactions

Vaginal bleeding, breast tenderness, vaginal candidiasis; thromboembolism, neoplasms.

Femring Clinical Trials

See Literature

Femring Note

Not Applicable

Femring Patient Counseling

See Literature