Conjugated estrogens (Oral)
Generic name: conjugated estrogens [ KON-joo-gay-ted-ES-troe-jenz ]
Brand name: Premarin
Drug class: Estrogens
Medically reviewed by Drugs.com. Last updated on Aug 6, 2024.
Endometrial Cancer, Cardiovascular Disorders, Breast Cancer and Probable Dementia
Estrogen-Alone Therapy
There is an increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens.
Estrogen-alone therapy should not be used for the prevention of cardiovascular disease or dementia.
Women's Health Initiative estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis.
The Women’s Health Initiative Memory Study estrogen-alone ancillary study of Women’s Health Initiative reported an increased risk of probable dementia in postmenopausal women 65 years of age and older.
Estrogen Plus Progestin Therapy
Estrogen plus progestin therapy should not be used for the prevention of cardiovascular disease or dementia.
The Women’s Health Initiative estrogen plus progestin substudy reported increased risks of stroke, DVT, pulmonary embolism, and myocardial infarction.
The Women’s Health Initiative estrogen plus progestin substudy reported increased risks of invasive breast cancer.
The Women’s Health Initiative Memory Study estrogen plus progestin ancillary study of Women’s Health Initiative reported an increased risk of probable dementia in postmenopausal women 65 years of age and older .
Uses for conjugated estrogens
Conjugated estrogens are a medicine that contains a mixture of estrogen hormones. It is used to treat moderate to severe hot flashes, changes in and around the vagina, and other symptoms of menopause or low amounts of estrogen (hypoestrogenism). This medicine is also used to prevent osteoporosis (thinning of the bones) after menopause.
Conjugated estrogens tablet is also used to treat symptoms of breast and prostate cancer that have spread through the body in men and women. It is also used to treat certain conditions in women before menopause if their ovaries do not make enough estrogen naturally.
This medicine is available only with your doctor's prescription.
Before using conjugated estrogens
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Allergies
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Pediatric
Appropriate studies on the relationship of age to the effects of conjugated estrogens have not been performed in the pediatric population. However, pediatric-specific problems that would limit the usefulness of this medication in teenagers are not expected.
Geriatric
Although appropriate studies on the relationship of age to the effects of conjugated estrogens have not been performed in the geriatric population, no geriatric-specific problems have been documented to date. However, elderly patients are more likely to have breast cancer, stroke, or dementia, which may require caution in patients receiving conjugated estrogens.
Breast Feeding
Studies suggest that this medication may alter milk production or composition. If an alternative to this medication is not prescribed, you should monitor the infant for side effects and adequate milk intake.
Interactions with Medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Amifampridine
- Bupropion
- Donepezil
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Etoricoxib
- Ginseng
- Levothyroxine
- Licorice
- Tipranavir
Interactions with Food/Tobacco/Alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other Medical Problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Abnormal or unusual vaginal bleeding or
- Blood clots (e.g., deep vein thrombosis, pulmonary embolism), active or history of or
- Breast cancer, known or suspected, or a history of or
- Heart attack, active or history of or
- Liver disease or
- Protein C, protein S, or other known blood clotting disorders or
- Stroke, active or history of or
- Tumors (estrogen-dependent), known or suspected—Should not be used in patients with these conditions.
- Asthma or
- Cancer, history of or
- Diabetes or
- Edema (fluid retention or body swelling) or
- Endometriosis or
- Epilepsy (seizures) or
- Gallbladder disease or
- Heart disease or
- Hereditary angioedema (swelling of the face, lips, tongue, or throat) or
- Hypercalcemia (high calcium in the blood) or
- Hypertension (high blood pressure) or
- Hypertriglyceridemia (high triglycerides or fats in the blood) or
- Hypocalcemia (low calcium in the blood), severe or
- Hypothyroidism (an underactive thyroid) or
- Jaundice during pregnancy or from using hormonal therapy in the past or
- Liver tumors or
- Migraine headache or
- Porphyria (an enzyme problem) or
- Systemic lupus erythematosus (SLE)—Use with caution. May make these conditions worse.
Proper use of conjugated estrogens
It is very important that you use this medicine only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. To do so may cause unwanted side effects.
This medicine comes with a patient information leaflet. Read and follow the instructions in the leaflet carefully. Ask your doctor if you have any questions.
You may take this medicine with or without food.
It is important that you eat a well-balanced diet with an adequate amount of calcium and vitamin D (found in milk or other dairy products). It is recommended that you receive calcium and vitamin D supplements while receiving this medicine.
Dosing
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For oral dosage form (tablets):
- For prevention of hot flashes, vulvar and vaginal atrophy caused by menopause or osteoporosis after menopause:
- Adults—At first, 0.3 milligram (mg) once a day. Your doctor may adjust your dose as needed. The medicine may be taken everyday, or in cycles (taking the medicine for 25 days, followed by 5 days without medicine).
- Children—Use and dose must be determined by your doctor.
- For treatment of advanced prostate cancer in men:
- Adults—1.25 to 2.5 (taken as two tablets) milligrams (mg) three times a day.
- Children—Use and dose must be determined by your doctor.
- For treatment of breast cancer in men and women:
- Adults—10 milligrams (mg) three times a day, for at least 3 months.
- Children—Use and dose must be determined by your doctor.
- For treatment of hypoestrogenism due to female hypogonadism:
- Adults—0.3 to 0.625 milligram (mg) once a day, taken in cycles (taking the medicine for 3 weeks, followed by 1 week without medicine). Your doctor may adjust your dose as needed.
- Children—Use and dose must be determined by your doctor.
- For treatment of hypoestrogenism due to female castration or primary ovarian failure:
- Adults—1.25 milligrams (mg) once a day, taken in cycles (taking the medicine for 3 weeks, followed by 1 week without medicine). Your doctor may adjust your dose as needed.
- Children—Use and dose must be determined by your doctor.
- For prevention of hot flashes, vulvar and vaginal atrophy caused by menopause or osteoporosis after menopause:
Missed Dose
If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
Storage
Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.
Keep out of the reach of children.
Do not keep outdated medicine or medicine no longer needed.
Ask your healthcare professional how you should dispose of any medicine you do not use.
Related/similar drugs
alendronate, estradiol, tamoxifen, Prolia, Fosamax, calcium carbonate, testosterone, Premarin, norethindrone
Precautions while using conjugated estrogens
It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and does not cause unwanted effects. Pelvic exam, breast exam, and mammogram (breast x-ray) may be needed to check for unwanted effects, unless your doctor tells you otherwise.
Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using the medicine, tell your doctor right away.
Using large doses of this medicine over a long period of time may increase your risk of heart attack, stroke, blood clots, dementia, breast cancer, or uterine cancer. Talk with your doctor about this risk. If you still have your uterus (womb), ask your doctor if you should also use a progestin medicine.
Your risk of heart disease or stroke from this medicine is higher if you smoke. Your risk is also increased if you have diabetes or high cholesterol, or if you are overweight. Talk with your doctor about ways to stop smoking. Keep your diabetes under control. Ask your doctor about diet and exercise to control your weight and blood cholesterol level.
Tell the medical doctor or dentist in charge that you are using this medicine before any kind of surgery (including dental surgery) or emergency treatment. Your doctor will decide whether you should continue using this medicine.
Using this medicine alone may increase your risk of getting cancer of the uterus (womb). Check with your doctor right away if you have unusual vaginal bleeding while you are using this medicine.
Stop using this medicine and check with your doctor immediately if severe headache or sudden loss of vision or any other change in vision occurs while you are using this medicine. Your doctor may want you to have your eyes checked by an ophthalmologist (eye doctor).
This medicine may cause a serious type of allergic reaction called anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash; itching; hoarseness; trouble breathing; trouble swallowing; or any swelling of your hands, face, mouth, or throat while you are using this medicine.
Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests may be affected by this medicine.
Side Effects of conjugated estrogens
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
- Heavy non-menstrual vaginal bleeding
Less common
- Body aches or pain
- chills
- cough
- difficulty with breathing
- ear congestion
- fever
- headache
- loss of voice
- nasal congestion
- runny nose
- sneezing
- sore throat
- unusual tiredness or weakness
Incidence not known
- Abdominal or stomach pain and tenderness
- acid or sour stomach
- anxiety
- backache
- belching
- bloody stools
- blurred vision
- breast tenderness, enlargement, pain, or discharge
- change in vaginal discharge
- change in vision
- changes in skin color
- chest pain or discomfort
- clay-colored stools
- clear or bloody discharge from the nipple
- confusion
- constipation
- dark urine
- diarrhea
- difficulty with speaking
- dimpling of the breast skin
- dizziness or lightheadedness
- double vision
- fainting
- fast heartbeat
- full or bloated feeling or pressure in the stomach
- headache, severe and throbbing
- heartburn
- hives
- hoarseness
- inability to move the arms, legs, or facial muscles
- inability to speak
- indigestion
- inverted nipple
- irritation
- itching
- joint pain, stiffness, or swelling
- loss of appetite
- lump in the breast or under the arm
- migraine headache
- nausea
- pain or discomfort in the arms, jaw, back, or neck
- pain or feeling of pressure in the pelvis
- pain, redness, or swelling in the arm or leg
- pain, tenderness, or swelling of the foot or leg
- painful or tender cysts in the breasts
- pains in the stomach, side, or abdomen, possibly radiating to the back
- persistent crusting or scaling of the nipple
- poor insight and judgment
- problems with memory or speech
- rash
- rectal bleeding
- redness of the skin
- redness or swelling of the breast
- shortness of breath
- slow speech
- sore on the skin of the breast that does not heal
- stomach discomfort or upset
- sudden shortness of breath or troubled breathing
- sweating
- swelling of the abdominal or stomach area
- swelling of the eyelids, face, lips, hands, or feet
- tightness in the chest
- trouble recognizing objects
- trouble thinking and planning
- trouble walking
- troubled breathing or swallowing
- unpleasant breath odor
- vaginal bleeding
- vomiting
- vomiting of blood
- wheezing
- yellow eyes or skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
- Back pain
- excess air or gas in the stomach or intestines
- itching of the vagina or genital area
- lack or loss of strength
- pain during sexual intercourse
- passing gas
- thick, white vaginal discharge with no odor or with a mild odor
Less common
- Increased clear or white vaginal discharge
- leg cramps
Incidence not known
- Blistering, peeling, or loosening of the skin
- cramps
- decreased interest in sexual intercourse
- diarrhea
- difficulty with moving
- heavy bleeding
- hives or welts
- inability to have or keep an erection
- increased hair growth, especially on the face
- increased in sexual ability, desire, drive, or performance
- increased interest in sexual intercourse
- irritability
- itching of the vagina or outside genitals
- joint or muscle pain
- loss in sexual ability, desire, drive, or performance
- loss of scalp hair
- mental depression
- mood changes
- muscle stiffness
- pain
- pain during sexual intercourse
- pain in the ankles or knees
- painful, red lumps under the skin, mostly on the legs
- patchy brown or dark brown discoloration of the skin
- rash
- red, irritated eyes
- sores, ulcers, or white spots in the mouth or on the lips
- swelling of the breasts or breast soreness in both females and males
- thick, white curd-like vaginal discharge without odor or with mild odor
- unexpected or excess milk flow from the breasts
- weight changes
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Commonly used brand name(s)
In the U.S.
- Premarin
Available Dosage Forms:
- Tablet
Therapeutic Class: Endocrine-Metabolic Agent
Pharmacologic Class: Estrogen
More about conjugated estrogens
- Check interactions
- Compare alternatives
- Reviews (93)
- Side effects
- Dosage information
- During pregnancy
- Drug class: estrogens
- En español
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Other brands
Professional resources
Other brands
Premarin, Cenestin, Premarin Intravenous
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Further information
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