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estrogens, conjugated (estrogenic substances, conjugated; oestrogens, conjugated)
C.E.S.†, Premarin, Premarin Intravenous

Pregnancy Risk Category X

How supplied
Tablets:
0.3 mg, 0.625 mg, 0.9 mg, 1.25 mg, 2.5 mg
Injection:
25 mg/5 ml
Vaginal cream:
0.625 mg/g

Action
Increases synthesis of DNA, RNA, and protein in responsive tissues. Also reduces release of follicle-stimulating and luteinizing hormones from the pituitary gland.

Indications & dosage
Abnormal uterine bleeding (hormonal imbalance)--

Women:
25 mg I.V. or I.M., repeated in 6 to 12 hours, p.r.n.
Palliative treatment of breast cancer (at least 5 years after menopause)--

Men and postmenopausal women:
10 mg P.O. t.i.d. for 3 months or more.
Female castration, primary ovarian failure--

Women:
1.25 mg P.O. daily in cycles of 3 weeks on and 1 week off. Can be given continuously.
Osteoporosis--

Postmenopausal women:
0.625 mg P.O. daily in cyclic regimen (3 weeks on, 1 week off). Can be given continuously.
Hypogonadism--

Women:
2.5 to 7.5 mg daily in divided doses for 20 days followed by 10 days off.
Vasomotor menopausal symptoms--

Women:
0.3 to 1.25 mg P.O. daily in cycles of 3 weeks on and 1 week off. Can be given continuously.
Atrophic vaginitis, kraurosis vulvae
--
Women:
0.5 to 2 g intravaginally once daily on a cyclical basis (3 weeks on and 1 week off).
Palliative treatment of inoperable prostate cancer--

Men:
1.25 to 2.5 mg P.O. t.i.d.

Adverse reactions
CNS:
headache, dizziness, chorea, depression, seizures.
CV:
thrombophlebitis; thromboembolism; hypertension; edema; increased risk of CVA, pulmonary embolism, MI.
EENT:
worsening myopia or astigmatism, intolerance of contact lenses.
GI:
nausea, vomiting, abdominal cramps, bloating, anorexia, increased appetite, pancreatitis.
GU:
breakthrough bleeding, altered menstrual flow, dysmenorrhea, amenorrhea, increased risk of endometrial cancer, cervical erosion, altered cervical secretions, enlargement of uterine fibromas, vaginal candidiasis; gynecomastia, testicular atrophy, impotence.
Hematologic:
increased PT and clotting factors VII to X, and norepinephrine-induced platelet aggregation.
Hepatic:
cholestatic jaundice, hepatic adenoma.
Metabolic:
weight changes.
Skin:
melasma, urticaria, flushing with rapid I.V. administration, hirsutism or hair loss, erythema nodosum, dermatitis.
Other:
gallbladder disease; breast tenderness, enlargement, or secretion; possible increased risk of breast cancer.

Interactions
Drug-drug.
Carbamazepine, phenobarbital, rifampin: decreased effectiveness of estrogen therapy. Monitor closely.
Corticosteroids:
possible enhanced effects of corticosteroids. Monitor closely.
Cyclosporine:
increased risk of toxicity. Use together with caution and frequently monitor cyclosporine levels.
Dantrolene, other hepatotoxic drugs:
increased risk of hepatotoxicity. Monitor closely.
Oral anticoagulants:
effect of anticoagulant may be decreased. Dosage adjustments may be needed. Monitor PT and INR, as ordered.
Tamoxifen:
estrogens may interfere with effectiveness of tamoxifen. Avoid concomitant use.
Drug-food.
Caffeine: may increase serum caffeine levels. Monitor effects.
Drug-lifestyle.
Smoking: increased risk of adverse CV effects. If smoking continues, may need alternative therapy.

Effects on diagnostic tests
Glucose tolerance may be impaired. Reduced response to metyrapone test.

Contraindications
Contraindicated in patients with thrombophlebitis or thromboembolic disorders, estrogen-dependent neoplasia, breast or reproductive cancer (except for palliative treatment), or undiagnosed abnormal genital bleeding; also contraindicated during pregnancy.

Nursing considerations

I.V. administration

Patient teaching

*Liquid contains alcohol. **May contain tartrazine.  †Canada  ‡Australia  §U.K.  OTCOver the counter
Reactions may be common, uncommon, life-threatening, or COMMON AND LIFE-THREATENING

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