Estrogens, conjugated Other names: Premarin

Estrogens should not be used during pregnancy. There appears to be little or no increased risk of birth defects in children born to women who have used estrogens and progestins as an oral contraceptive inadvertently during early pregnancy.

Estrogens should not be used during lactation. Estrogen administration to nursing women has been shown to decrease the quantity and quality of the breast milk. Detectable amounts of estrogens have been identified in the breast milk of mothers receiving estrogen-alone therapy. Caution should be exercised when estrogens is administered to a nursing woman.

Long-term continuous administration of natural and synthetic estrogens in certain animal species increases the frequency of carcinomas of the breast, uterus, cervix, vagina, testis, and liver.

No studies on the effect of ability to drive or use machines have been performed.

The following serious adverse reactions are discussed elsewhere in labeling:

• Cardiovascular Disorders
• Malignant Neoplasms

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

During the first year of a 2-year clinical trial with 2,333 postmenopausal women with a uterus between 40 and 65 years of age (88 percent Caucasian), 1,012 women were treated with conjugated estrogens, and 332 were treated with placebo.

Table 1 summarizes treatment-related adverse reactions that occurred at a rate of ≥1 percent in any treatment group.

Table 1. Treatment Related Adverse Reactions at a Frequency ≥1 Percent:

Postmarketing Experience

The following additional adverse reactions have been identified during post-approval use of oral estrogens, conjugated (tablet). Because these reactions are reported voluntarily from a population of uncertain size, it is not possible always to reliably estimate their frequency or establish a causal relationship to drug exposure.

Genitourinary system

Abnormal uterine bleeding; dysmenorrheal or pelvic pain, increase in size of uterine leiomyomata, vaginitis, including vaginal candidiasis, change in cervical secretion, ovarian cancer, endometrial hyperplasia, endometrial cancer, leukorrhea.

Breasts

Tenderness, enlargement, pain, discharge, galactorrhea, fibrocystic breast changes, breast cancer, gynecomastia in males.

Cardiovascular

Deep and superficial venous thrombosis, pulmonary embolism, thrombophlebitis, myocardial infarction, stroke, increase in blood pressure.

Gastrointestinal

Nausea, vomiting, abdominal pain, bloating, cholestatic jaundice, increased incidence of gallbladder disease, pancreatitis, enlargement of hepatic hemangiomas, ischemic colitis.

Skin

Chloasma or melasma that may persist when drug is discontinued, erythema multiforme, erythema nodosum, loss of scalp hair, hirsutism, pruritus, rash.

Eyes

Retinal vascular thrombosis, intolerance to contact lenses.

Central nervous system

Headache, migraine, dizziness, mental depression, nervousness, mood disturbances, irritability, exacerbation of epilepsy, dementia, possible growth potentiation of benign meningioma.

Miscellaneous

Increase or decrease in weight, glucose intolerance, aggravation of porphyria, edema, arthralgias, leg cramps, changes in libido, urticaria, exacerbation of asthma, increased triglycerides, hypersensitivity.