Generic name: conjugated estrogens (oral) [ KON-joo-gay-ted-ES-troe-jenz ]
Brand names: Premarin, Premarin Intravenous, Cenestin, Enjuvia
Dosage form: oral tablet (0.3 mg; 0.45 mg; 0.625 mg; 0.9 mg; 1.25 mg)
Drug class: Estrogens

Medically reviewed by Drugs.com on Feb 29, 2024. Written by Cerner Multum.

What is conjugated estrogens?

Estrogen is a female sex hormone produced by the ovaries. Estrogen is necessary for many processes in the body.

Conjugated estrogens are a mixture of estrogen hormones used to treat menopause symptoms such as hot flashes and vaginal changes, and to prevent osteoporosis (bone loss) in menopausal women. Conjugated estrogens are also used to replace estrogen in women with ovarian failure or other conditions that cause a lack of natural estrogen in the body.

Conjugated estrogens are sometimes used as part of cancer treatment in both women and men.

Conjugated estrogens may also be used for purposes not listed in this medication guide.

Conjugated estrogens side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Conjugated estrogens may cause serious side effects. Call your doctor at once if you have:

• heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, sweating;

• signs of a stroke--sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance;

• signs of a blood clot--sudden vision loss, stabbing chest pain, coughing up blood, pain or warmth in one or both legs;

• swelling, rapid weight gain;

• jaundice (yellowing of the skin or eyes);

• memory problems, confusion, unusual behavior;

• unusual vaginal bleeding, pelvic pain;

• a lump in your breast; or

• high levels of calcium in your blood--vomiting, constipation, increased thirst or urination, muscle weakness, bone pain, lack of energy.

Common side effects of conjugated estrogens may include:

• swelling;

• hair loss;

• numbness, tingling, burning pain;

• back pain, leg cramps, pain;

• bloating, gas, indigestion, nausea, vomiting, stomach pain;

• dizziness, headache;

• breast pain; or

• vaginal itching or discharge, changes in your menstrual periods, breakthrough bleeding.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Warnings

You should not use conjugated estrogens if you have: undiagnosed vaginal bleeding, liver disease, a bleeding disorder, if you will have major surgery, or if you have ever had a heart attack, a stroke, a blood clot, or cancer of the breast, uterus/cervix, or vagina.

Do not use if you are pregnant.

Conjugated estrogens may increase your risk of developing a condition that can lead to uterine cancer. Report any unusual vaginal bleeding right away.

Using this medicine can increase your risk of blood clots, stroke, heart attack, or cancer of the breast, uterus, or ovaries. Estrogen should not be used to prevent heart disease, stroke, or dementia.

Before taking this medicine

You should not use conjugated estrogens if you are allergic to it, or if you have:

• unusual vaginal bleeding that has not been checked by a doctor;

• liver disease;

• a history of heart attack, stroke, or blood clot;

• an increased risk of having blood clots due to a heart problem or a hereditary blood disorder; or

• a history of hormone-related cancer, or cancer of the breast, uterus/cervix, or vagina.

Do not use conjugated estrogens if you are pregnant. Tell your doctor right away if you become pregnant during treatment.

Using this medicine can increase your risk of blood clots, stroke, or heart attack. You are even more at risk if you have high blood pressure, diabetes, high cholesterol, if you are overweight, or if you smoke.

Estrogen should not be used to prevent heart disease, stroke, or dementia. This medicine may actually increase your risk of developing these conditions.

Tell your doctor if you have ever had:

• a hysterectomy;

• heart disease;

• liver problems, or jaundice caused by pregnancy or taking hormones;

• kidney disease;

• gallbladder disease;

• asthma;

• epilepsy or other seizure disorder;

• migraines;

• lupus;

• endometriosis or uterine fibroid tumors;

• hereditary angioedema;

• porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system);

• a thyroid disorder; or

• high levels of calcium in your blood.

Using conjugated estrogens may increase your risk of cancer of the breast, uterus, or ovaries. Talk with your doctor about this risk.

It may not be safe to breastfeed while using this medicine. Estrogen can slow breast milk production. Tell your doctor if your are breastfeeding.

How should I take conjugated estrogens?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Conjugated estrogens may increase your risk of developing a condition that can lead to uterine cancer. To help lower this risk, your doctor may also want you to take a progestin. Report any unusual vaginal bleeding right away.

Conjugated estrogens are sometimes taken on a daily basis. For certain conditions, the medicine is given in a cycle, such as 3 weeks on followed by 1 week off. Follow your doctor's instructions.

If you see what looks like part of a conjugated estrogen tablet in your stool, talk with your doctor.

Your doctor should check your progress on a regular basis to determine whether you should continue this treatment. Self-examine your breasts for lumps on a monthly basis, and have regular mammograms.

If you need major surgery or will be on long-term bed rest, you may need to stop using conjugated estrogens for a short time. Any doctor or surgeon who treats you should know that you are using conjugated estrogens.

Store at room temperature away from moisture, heat, and light.

Related/similar drugs

alendronate, estradiol, tamoxifen, Prolia, Fosamax, calcium carbonate, testosterone, Premarin, megestrol

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking conjugated estrogens?

Avoid smoking. It can greatly increase your risk of blood clots, stroke, or heart attack while using conjugated estrogens.

Grapefruit may interact with conjugated estrogens and lead to unwanted side effects. Avoid the use of grapefruit products.

What other drugs will affect conjugated estrogens?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect conjugated estrogens. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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