Premarin (Conjugated Estrogens)
Complete patient guide for uses, dosage, side effects, and safety information
Prescription RequiredQuick Facts
What Is Premarin Used For?
Premarin contains conjugated estrogens and is a type of menopausal hormone therapy (MHT) that helps replace the estrogen your body produces less of during menopause.
Primary Uses
Premarin is used to relieve menopause symptoms like hot flushes, sweating, and vaginal dryness. It also helps prevent bone thinning (osteoporosis) that can lead to fractures. Additionally, it treats women whose ovaries don’t function properly or have been removed.
How It Works
During menopause, your body produces less estrogen, causing symptoms like hot flushes and vaginal dryness. Some women also develop osteoporosis, where bones become thinner and more likely to break. Conjugated estrogens work like the hormones your ovaries produced before menopause, helping to control these symptoms.
Good to know: If you have not had your uterus removed, you will need to take an estrogen with a progestogen for safety.
How to Take Premarin
Take Premarin at the same time each day as directed by your doctor. It doesn’t matter if you take it before or after food.
Dosage Instructions
For osteoporosis prevention: take one tablet daily. For menopause symptoms: take one or two tablets daily as instructed by your doctor. For women without fully-functioning ovaries: your doctor will prescribe according to your needs. Swallow tablets whole with a full glass of water – do not divide, crush, chew, or dissolve them.
What If You Miss a Dose?
If more than 12 hours has passed since your usual time, skip the missed dose and take your next dose when scheduled. If less than 12 hours has passed, take the missed tablet and then take the next tablet at the usual time.
Important: Do not take a double dose to make up for a missed dose.
Available Tablet Strengths
Side Effects
Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.
Common Side Effects
These side effects occur relatively frequently and usually don’t require emergency care:
- Abnormal bleeding or spotting
- Period-like pain or pelvic pain
- Changes to vaginal discharge
- Sore, swollen or irritated breasts
- Weight changes
- Acne or rash
- Changes to mood
- Nausea or vomiting
- Headache or migraine
- Dizziness
- Breast tenderness
- Stomach pain
Seek immediate medical attention if you experience:
- Signs of stroke (sudden severe headache, loss of coordination, blurred vision, slurred speech, numbness/tingling in arm or leg)
- Signs of heart attack (chest pain)
- Signs of blood clots (painful swelling in calves/thighs, difficulty breathing, coughing blood)
- Sudden partial or complete vision loss
- Lumps in breast or armpit
- Shortness of breath or wheezing
- Swelling of face, lips, tongue
- Severe skin reactions
- Yellowing of skin or eyes
- Severe abdominal pain with fever
Important Warnings
Premarin has important safety warnings including increased risks of certain serious conditions. Your doctor will assess the risks and benefits with you.
Who Should Not Take Premarin
Do not take if you are allergic to conjugated estrogens or similar medicines, have or had breast cancer, endometrial/ovarian/cervical cancer, abnormal genital bleeding, blood clots, heart disease, stroke, uncontrolled high blood pressure, liver disease, blood clotting problems, or are pregnant.
Medical Conditions to Discuss
Tell your doctor if you have breast lumps/cysts, fibroids, unusual bleeding, endometriosis, high blood pressure, liver problems, porphyria, hearing difficulties, jaundice history, fluid retention, kidney/heart problems, diabetes, migraine, asthma, epilepsy, lupus, hereditary angioedema, dementia, gall bladder disease, high triglycerides, calcium level problems, underactive thyroid, obesity, family history of breast cancer or blood clots, or if you smoke.
Pregnancy and Breastfeeding
Do not take Premarin if you are pregnant, think you are pregnant, or are breastfeeding. You must confirm you are not pregnant before starting. Premarin is not a contraceptive – use non-hormonal birth control if pregnancy is possible. Estrogens are found in breast milk and may reduce milk production.
Serious Health Risks: Premarin should not be used to prevent heart disease or dementia. It may increase your risk of stroke, blood clots, or dementia over time. When combined with progestogen, it may increase risk of heart attack, stroke, breast cancer, blood clots, or dementia. Use at the lowest effective dose for the shortest time possible.
Drug Interactions
Some medicines may interfere with how Premarin works or increase side effects. Always tell your doctor about all medicines you’re taking.
Grapefruit interaction: Grapefruit juice may affect how well Premarin works.
- St John’s Wort
- Epilepsy medicines (phenytoin, phenobarbitone, carbamazepine)
- Antibiotics (rifampicin, erythromycin, clarithromycin)
- Corticosteroids (dexamethasone)
- Cimetidine
- Anti-fungal agents (ketoconazole, itraconazole)
- Thyroid replacement therapy
- Ritonavir (HIV medicine)
- Cyclosporin
- Lamotrigine
- Blood pressure medicines
- Depression/anxiety medicines (tricyclic antidepressants, diazepam, phenothiazines)
- Theophylline
Alcohol & Driving
Be careful when driving or using machinery until you know how Premarin affects you.
Alcohol
No specific information available about alcohol interactions with Premarin.
Driving and Operating Machinery
Premarin may cause dizziness in some people. Be careful before you drive or use any machines or tools until you know how Premarin affects you.
Storage
Keep your tablets where the temperature stays below 25°C. Keep tablets in the blister pack until it’s time to take them – if you remove them, they may not keep well. Store in a cool dry place away from moisture, heat or sunlight. Don’t store in the bathroom, near a sink, in the car, or on window sills. Keep away from children.
Overdose Information
If you think you have taken too much Premarin, seek urgent medical attention immediately. Phone the Poisons Information Centre (13 11 26), contact your doctor, or go to the nearest hospital Emergency Department, even if you feel fine. Overdose symptoms may include feeling sick, vomiting, dizziness, sleepiness, tiredness, breast tenderness, stomach pain, and vaginal bleeding in women.
Frequently Asked Questions
The source doesn’t specify exact timing, but breakthrough bleeding or spotting may occur during the first few months of treatment and then stop as your body adjusts to the medication.
Yes, it doesn’t matter if you take Premarin before or after food. Take it at the same time each day as directed by your doctor.
If more than 12 hours has passed since your usual time, skip the missed dose and take your next dose when scheduled. If less than 12 hours has passed, take the missed tablet and then take the next tablet at the usual time. Never double dose.
The source states that no information is available about alcohol interactions with Premarin. Consult your doctor for specific advice about alcohol consumption.
Weight changes are listed as a possible side effect of Premarin. If you experience unexplained weight loss or gain that continues for a few weeks, tell your doctor.
Do not stop taking Premarin or change the dosage without checking with your doctor first. Talk regularly with your doctor about whether you still need treatment.
See your doctor at least every six months for a checkup. Some women may need to go more often. Your doctor will regularly check your breasts, send you for mammograms, check your uterus and cervix, do Pap smears, and monitor your blood pressure.
Important Disclaimer
This information is intended for general educational purposes only and should not be considered medical advice. Always consult your healthcare provider or pharmacist before starting, stopping, or changing any medication.
If you think you may have a medical emergency, call your doctor or emergency services immediately.