Other Brands/Names

Esthero, Premarin

How It Works

Estrogen medicines are used to relieve symptoms caused by a lack of estrogen, which most often occurs after menopause. As part of hormone replacement therapy, estrogen is available in several forms, including conjugated estrogen.

Conjugated estrogen is a blend of multiple estrogen hormones. By giving conjugated estrogen, overall estrogen levels in the body can be raised, which helps address symptoms that arise from this hormone deficiency.

Indications

Estrogen is indicated for hormone replacement therapy to manage estrogen deficiency in the following conditions:

• Hypogonadism, a condition in which the sex glands do not produce sufficient hormones.
• Primary ovarian failure, where the ovaries stop functioning before age 40.

Complaints commonly experienced by menopausal women due to low estrogen include:

• Hot flashes, a sensation of heat and flushing over the face, neck, and chest.
• Vaginal dryness.
• Pain during intercourse.

This medicine is also used to help prevent osteoporosis in postmenopausal women and to treat certain cancers.

Contraindication

Do not use in patients with:

• Hypersensitivity or allergy.
• A past or current history of breast cancer.
• Cardiovascular disorders such as stroke or blood clots.
• Endometrial cancer.
• Porphyria, an inherited blood disorder that leads to porphyrin buildup.
• Conditions that increase the tendency to form clots.
• Liver disorders.
• Unexplained genital bleeding.
• Pregnancy.

Side Effects

Possible side effects include:

• Nausea
• Stomach pain
• Weight changes
• Weakness
• Leg cramps
• Back pain
• Headache
• Itching or skin rash

Although uncommon, serious adverse effects may also occur, such as:

• Mood changes, including depression
• Breast enlargement
• Unusual vaginal bleeding
• Severe allergic reactions, including generalized rash, swelling, or shortness of breath
• Increased risk of gallbladder problems
• Blood clots

Estradiol may also cause dark patches on the face and skin, known as melasma.

Types

Sugar-coated caplets in strengths of 0.3 mg, 0.625 mg, and 1.25 mg.

Dosage

Management of menopausal estrogen-deficiency symptoms and prevention of osteoporosis in postmenopausal women:

• Dose: 0.3 mg once daily.
• This medicine may be taken every day or given in cycles (3 weeks on and 1 week off, or 25 days on and 5 days off). Doses and schedules are adjusted to the patient’s condition.

Treatment of estrogen deficiency due to hypogonadism:

• Dose: 0.3 or 0.625 mg once daily.
• This medicine can be used in cycles (3 weeks on and 1 week off, or 25 days on and 5 days off).
• Dose increases may be considered at 6–12 month intervals.

Safety

Do not use during pregnancy. This medicine passes into breast milk; consult your doctor before breastfeeding.

Drug Interactions

• The risk of stroke, blood clots, hypertension, and heart attack may rise if the patient smokes while taking estrogen.
• Estrogen levels may increase, raising the chance of side effects, when given with CYP3A4 inhibitors such as:
  
  • Erythromycin (antibiotic)
  • Ritonavir (antiviral)
• Estrogen levels may decrease, reducing effectiveness, when given with CYP3A4 inducers such as:
  
  • Rifampicin (antituberculosis)
  • Phenytoin (anticonvulsant)

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