Trade Names:Cenestin- Tablets 0.3 mg (conjugated estrogens, synthetic A)- Tablets 0.45 mg (conjugated estrogens, synthetic A)- Tablets 0.625 mg (conjugated estrogens, synthetic A)- Tablets 0.9 mg (conjugated estrogens, synthetic A)- Tablets 1.25 mg (conjugated estrogens, synthetic A)
Trade Names:Enjuvia- Tablets 0.3 mg (conjugated estrogens, synthetic B)- Tablets 0.45 mg (conjugated estrogens, synthetic B)- Tablets 0.625 mg (conjugated estrogens, synthetic B)- Tablets 1.25 mg (conjugated estrogens, synthetic B)
Estrogens are responsible for the development and maintenance of the female reproductive system and secondary sexual characteristics. Circulating estrogens modulate the pituitary secretion of the gonadotropins luteinizing hormone and follicle-stimulating hormone through a negative-feedback mechanism and estrogen replacement therapy acts to reduce the elevated levels of these hormones seen in postmenopausal women.
Well absorbed from the GI tract. Absorbed slowly from the product over a period of several hours.
Widely distributed in the body and generally found in higher concentrations in sex hormone target organs. Largely bound to sex hormone–binding globulin and albumin.
Partially metabolized by CYP3A4. Metabolized mainly in the liver (estradiol converted to estrone and both are converted to estriol, a major urinary metabolite). Estrogens undergo enterohepatic recirculation via sulfate and glucuronide conjugates in the liver, biliary secretion of conjugates into the intestine, and hydrolysis in the gut followed by reabsorption.
Estradiol, estrone, and estriol are excreted in the urine along with glucuronide and sulfate conjugates.
No pharmacokinetic studies have been conducted in special populations, including patients with renal or hepatic function impairment.
Treatment of moderate to severe symptoms associated with menopause; treatment of moderate to severe symptoms of vulvar and vaginal atrophy associated with menopause (0.3 mg only).
Known or suspected pregnancy; undiagnosed abnormal genital bleeding; known or suspected cancer of the breast; known or suspected estrogen-dependent neoplasia; active deep vein thrombosis, pulmonary embolism, or a history of these conditions; active or recent (within the past year) arterial thromboembolic disease (eg, stroke, MI); liver dysfunction or disease; hypersensitivity to estrogens.
POConjugated estrogens, synthetic A
Start with 0.45 mg/day and titrate dose based on response.Conjugated estrogens, synthetic B
Start with 0.3 mg/day, titrate dose based on patient response. Use the lowest effective dose for the shortest duration consistent with the treatment goals and risk.Vulvar and Vaginal AtrophyAdults
PO 0.3 mg/day.
Administer prescribed dose without regard to meals. Administer with food if GI upset occurs.
Store tablets at controlled room temperature (68° to 77°F).
Increased pharmacologic and toxicologic effects of corticosteroids may occur.Hydantoins (eg, phenytoin)
Loss of seizure control or decreased estrogenic effects may occur.Inducers of CYP3A4 (eg, carbamazepine, phenobarbital, rifampin, St. John's wort)
Estrogen concentration may be decreased, reducing the efficacy and changing the uterine bleeding profile.Inhibitors of CYP3A4 (eg, clarithromycin, erythromycin, grapefruit juice, itraconazole, ketoconazole, ritonavir)
May elevate estrogen concentrations, increasing the risk of adverse reactions.Thyroid hormones (eg, levothyroxine)
Serum-free thyroxine concentrations may be decreased, increasing serum thyrotropin concentrations and the need for thyroid hormone.
Accelerated PT, PTT, and platelet aggregation time with increased clotting factor activity; increased platelets; decreased anti-factor Xa and antithrombin III; increased thyroid-binding globulin (TBG) leading to increased total circulating thyroid hormone; increased plasma HDL, reduced LDL cholesterol, and increased triglycerides; impaired glucose tolerance; reduced response to metyrapone test; increased corticosteroid binding globulin and sex hormone binding globulin; increased factors II, VII antigen, VIII antigen, VIII coagulant activity, IX, X, XII, VII-X complex, II-VII-X complex, and beta-thromboglobulin; decreased antithrombin III activity, increased levels of fibrinogen and fibrinogen activity; increased plasminogen antigen and activity; decreased T3 resin uptake; decreased free hormone concentrations; other plasma proteins may be increased (eg, angiotensinogen/resin substrate).
Headache (68%); paresthesia (33%); dizziness (11%); anxiety, hypertonia, paresthesia (6%).
Abdominal pain (28%); nausea (12%); dyspepsia (10%); flatulence, vomiting (7%); constipation, diarrhea (6%).
Breast pain (29%); endometrial thickening (19%); metrorrhagia (14%); dysmenorrhea, vaginitis (8%).
Weight increase (6%).
Back pain (14%); leg cramps (10%).
Upper respiratory tract infection (13%); bronchitis, sinusitis (7%); increased cough (6%).
Pain (19%); infection (14%); accidental injury (8%); flu syndrome (7%).
WarningsCV and other risks
Estrogens with or without progestins should not be used for prevention of CV disease. The Women's Health Initiative (WHI) study reported increased risk of MI, stoke, invasive breast cancer, pulmonary emboli, and deep vein thrombosis in postmenopausal women 50 to 79 yr of age during 5.6 yr of treatment with oral conjugated estrogens 0.625 mg combined with medroxyprogesterone acetate 2.5 mg compared with placebo.Dementia
A substudy of WHI, the WHI Memory Study, reported increased risk of developing probable dementia in postmenopausal women 65 yr of age or older during 4 yr of treatment with oral conjugated estrogens plus medroxyprogesterone acetate compared with placebo. It is unknown if this finding applies to younger postmenopausal women or women taking estrogen alone.Endometrial cancer
Close clinical surveillance of all women taking estrogens is important. The use of unopposed estrogen in women with intact uteri has been associated with an increased risk of endometrial cancer. Diagnostic measures, including endometrial sampling when indicated, should be undertaken to rule out malignancy in all cases of undiagnosed persistent or recurring abnormal vaginal bleeding.
Monitor blood glucose in diabetic patients when starting or changing the dose of the drug.Baseline examinations
Ensure breast, abdominal, and pelvic examinations and Pap smear have been completed and documented before starting therapy and annually thereafter during prolonged therapy.
Contraindicated in pregnancy.
Excreted in breast milk. May reduce quantity and quality of breast milk.
Safety not established.
Insufficient data to determine if clinical response of subjects older than 65 yr of age is different from younger subjects.
Because asthma, diabetes mellitus, epilepsy, migraine, porphyria, systemic lupus erythematosus, and hepatic hemangiomas may be exacerbated by estrogens, use with caution.
Use of estrogens and progestins by postmenopausal women has been reported to increase the risk of breast cancer. Use of estrogen plus progestin has been reported to result in an increase in abnormal mammograms requiring further evaluation.
Substantial increases in BP have been attributed to idiosyncratic reactions to estrogens. Assess BP at beginning of therapy and periodically during treatment.
May be exacerbated with administration of estrogens.
Because estrogens may cause fluid retention, carefully monitor patients with conditions influenced by fluid retention (eg, cardiac dysfunction, renal function impairment).
Increased risk of gallbladder disease requiring surgery.
Use with caution and discontinue if there is recurrence.
Estrogen administration may lead to severe hypercalcemia in patients with breast cancer and bone metastases.
In patients with preexisting hypertriglyceridemia, estrogen therapy may be associated with elevations in plasma triglycerides, leading to pancreatitis and other complications.
Use with caution.
Estrogen administration leads to increased TBG levels. Ensure thyroid function is periodically monitored in patients with hypothyroidism and thyroid replacement dose is adjusted, if necessary, to maintain free thyroid levels in an acceptable range.
Estrogens may be poorly metabolized in patients with impaired liver function.
Estrogen plus progestin has been reported to increase the risk of cancer.
Consider discontinuing therapy during periods of prolonged immobilization and, if possible, 4 to 6 wk before surgery that is associated with an increased risk of thromboembolic disease.
Ensure attempts are made every 3 to 6 mo to discontinue therapy or reduce the dose of medication.
Retinal vascular thrombosis may occur, leading to loss of vision, sudden onset of proptosis, diplopia, or migraine.
Nausea, vomiting, withdrawal bleeding.
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