Toremifene | Side Effects, Dosage, Uses & More
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Generic Name:

toremifene, Oral tablet

All Brands

  • Fareston
SECTION 1 of 5

Highlights for toremifene

Oral tablet
1

Toremifene is an oral drug used to treat breast cancer that has spread to other parts of the body. It’s only used in postmenopausal women (women who have gone through menopause).

2

Toremifene works by blocking estrogen from attaching to the tumor cell. When the hormone can’t get to the cancer cell, the tumor growth may slow down and the cancerous cells may die.

3

Common side effects include nausea, hot flashes, sweating, and vaginal discharge.

4

Drinking grapefruit juice can increase the level of toremifene in your body. This raises your chances of side effects. You shouldn’t drink grapefruit juice while taking this medication.

5

The recommended dose is 60 mg taken once per day.

IMPORTANT INFORMATION

FDA warning

This drug has a Black Box Warning. This is the most serious warning from the Food and Drug Administration (FDA). A black box warning alerts doctors and patients to potentially dangerous effects.

QT prolongation warning. Between each beat that your heart takes, it needs to recharge itself for the next beat. QT prolongation occurs when your heart muscle takes longer to recharge itself in between beats. This can lead to a deadly heart rhythm, called Torsade de pointes. Your doctor should check your magnesium and potassium levels before starting you on toremifene. If either is too low, it may increase your risk of QT prolongation.

Tumor flare-up

In the first few weeks of treatment with toremifene, your tumors may temporarily increase in size. You may experience muscle pain and redness at the site of your bone tumors. This flare-up should go down with time. If your calcium levels get dangerously high, your doctor may stop treatment with toremifene. High calcium levels may be a sign of a tumor flare-up.

Endometrial cancer

Toremifene may raise your risk of endometrial cancer.

What is toremifene?

Toremifene is a prescription drug. It’s available as an oral tablet.

Toremifene isn’t available as a generic drug.

This drug may be used as part of a combination therapy. That means you need to take it with other drugs.

Why it's used

Toremifene is used to treat breast cancer that has spread to other parts of your body. It’s only used in postmenopausal women (women who have gone through menopause).

How it works

Toremifene belongs to a class of drugs called estrogen agonist/antagonist. A class of drugs refers to medications that work similarly.

More Details

How it works

Toremifene belongs to a class of drugs called estrogen agonist/antagonist. A class of drugs refers to medications that work similarly. They have a similar chemical structure and are often used to treat similar conditions.

Toremifene works by blocking estrogen from attaching to the tumor cell. When the hormone can’t get to the cancer cell, the tumor growth may slow down and the cancerous cells may die. 

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toremifene Side Effects

Oral tablet

Most Common Side Effects

The most common side effects that occur with toremifene include:

  • hot flashes

  • sweating

  • nausea

  • vaginal discharge

If these effects are mild, they may go away within a few days or a couple of weeks. If they’re more severe or don’t go away, talk to your doctor or pharmacist.

Serious Side Effects

If you experience any of these serious side effects, call your doctor right away. If your symptoms are potentially life threatening or if you think you’re experiencing a medical emergency, call 9-1-1.

  • high calcium levels and tumor flare. Symptoms include:

    • muscle pain
    • redness at the site of your bone tumors
  • heart attack or heart failure. Symptoms include:

    • chest pain
    • shortness of breath
    • nausea or vomiting
    • weight gain or fluid retention
  • cataracts or vision changes. Symptoms include:

    • blurred vision
    • dry eyes
  • blood clot in your lungs. Symptoms include:

    • shortness of breath
    • sharp chest pain
    • coughing up blood
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Toremifene doesn’t cause drowsiness.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this information includes all possible side effects. This information is not a substitute for medical advice. Always discuss possible side effects with a healthcare provider who knows your medical history.
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toremifene May Interact with Other Medications

Oral tablet

Toremifene can interact with other medications, herbs, or vitamins you might be taking. That’s why your doctor should manage all of your medications carefully. If you’re curious about how this drug might interact with something else you’re taking, talk to your doctor or pharmacist.

Note: You can reduce your chances of drug interactions by having all of your prescriptions filled at the same pharmacy. That way, a pharmacist can check for possible drug interactions.

Food interactions

Drinking grapefruit juice can increase the level of toremifene in your body. This can raise your chance of side effects. You shouldn’t drink grapefruit juice while you take this drug.

Alcohol interaction

Your body processes alcohol and this drug in similar ways. That means that if you drink alcohol, this drug might take longer to leave your body. You also could experience worse side effects.

Using alcohol while taking toremifene can also cause a sedative effect, which can be dangerous. It may lead to slowed reflexes, poor judgment, and sleepiness.

Medications that might interact with this drug

Antibiotics

When taken with toremifene, antibiotics can either raise your risk of the heart problem, QT prolongation, increase the amount or toremifene in your body, or do both.

These drugs include:

  • erythromycin
  • clarithromycin
  • levofloxacin
  • ofloxacin
  • telithromycin

Antifungals

These drugs can increase the amount of toremifene in your body. This can raise your risk of side effects.

These drugs include:

  • ketoconazole
  • itraconazole
  • voriconazole

Antipsychotic medicines

When taken with toremifene, these drugs can raise your risk of the heart problem, QT prolongation:

These drugs include:

  • thioridazine
  • haloperidol

Depression medicines

When taken with toremifene, these drugs can raise your risk of the heart problem, QT prolongation.

These drugs include:

  • tricyclic antidepressants or serotonin-norepinephrine reuptake inhibitors, such as:
    • venlafaxine
    • amitriptyline

Other drugs used to treat depression can increase the amount of toremifene in your body. This can raise your risk of side effects.

These drugs include:

  • selective serotonin reuptake inhibitor. such as:
    • nefazodone

Heart rate medications

When taken with toremifene, these drugs can raise your risk of the heart problem, QT prolongation:

These drugs include:

  • quinidine
  • procainamide
  • disopyramide
  • amiodarone
  • sotalol
  • ibutilide
  • dofetilide

Herbal supplements

These medications can decrease the amount of toremifene in your body. This means that it won’t work as well to treat your cancer.

These drugs include:

  • St. John’s wort

Human immunodeficiency virus (HIV) medications

These drugs can increase the amount of toremifene in your body. This can raise your risk of side effects.

These drugs include:

  • protease Inhibitors, such as:
    • atazanavir
    • indinavir
    • nelfinavir
    • ritonavir
    • saquinavir

Nausea medicines

When taken with toremifene, these drugs can raise your risk of the heart problem, QT prolongation.

These drugs include:

  • ondansetron
  • granisetron

Seizure medications

These medications can decrease the amount of toremifene in your body. This means that it won’t work as well to treat your cancer.

These drugs include:

  • phenytoin
  • phenobarbital
  • carbamazepine

Steroids

Certain steroids can decrease the amount of toremifene in your body. This means that it won’t work as well to treat your cancer.

These drugs include:

  • dexamethasone

Tuberculosis medications

These medications can decrease the amount of toremifene in your body. This means that it won’t work as well to treat your cancer.

These drugs include:

  • rifampin
  • rifabutin

Water pills (diuretics)

Toremifene increases your risk of dangerously high calcium levels. These medications affect how your body gets rid of calcium. This further increases your risk of high calcium levels.

These drugs include:

  • hydrochlorothiazide
  • chlorthalidone
  • metolazone
  • chlorothiazide

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs interact differently in each person, we cannot guarantee that this information includes all possible interactions. This information is not a substitute for medical advice. Always speak with your healthcare provider about possible interactions with all prescription drugs, vitamins, herbs and supplements, and over-the-counter drugs that you are taking.
Toremifene warnings
QT prolongation
People with QT prolongation

Toremifene can increase the time it takes for your heart muscle to recharge itself between heartbeats. This can lead to a deadly heart rhythm called Torsade de pointes. If you have a history of QT prolongation, you shouldn’t take toremifene.

Pregnant women
Pregnant women

Toremifene is a category D pregnancy drug. That means two things:

  1. Research in humans has shown adverse effects to the fetus when the mother takes the drug.
  2. This drug should only be used during pregnancy in serious cases where it's needed to treat a dangerous condition in the mother.

Talk to your doctor if you’re pregnant or planning to become pregnant. Ask your doctor to tell you about the specific harm that may be done to the fetus. This drug should be only used if the potential risk to the fetus is acceptable given the drug’s potential benefit.

breast-feeding
Women who are breast-feeding

It isn’t known if toremifene passes into breast milk. If it does, it may cause side effects in a child who is breast-fed.

This drug has been shown to prevent lactation in women.

Talk to your doctor if you breast-feed your baby. You may need to decide whether to stop breast-feeding or stop taking this medication.

seniors
For seniors

Older adults may process drugs more slowly. A normal adult dose may cause levels of the drug to build up higher than normal in your body. If you’re a senior, you may need a lower dose or a different dosing schedule.

For children
For children

This medicine hasn’t been studied in children and shouldn’t be used in people under the age of 18 years.

Allergies
Allergies

Toremifene can cause a severe allergic reaction. Symptoms include:

  • trouble breathing
  • swelling of your throat or tongue
  • hives

Don’t take this drug again if you’ve ever had an allergic reaction to it. Taking it again could be fatal (cause death).

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How to Take toremifene (Dosage)

Oral tablet

All possible dosages and forms may not be included here. Your dose, form, and how often you take it will depend on:

  • your age
  • the condition being treated
  • how severe your condition is
  • other medical conditions you have
  • how you react to the first dose

What are you taking this medication for?

Metastatic breast cancer

Brand: Fareston

Form: Oral tablet
Strengths: 60 mg
Adult dosage (ages 18–64 years)

60 mg taken one time per day.

Child dosage (ages 0–17 years)

This medicine hasn’t been studied in children and shouldn’t be used in people under the age of 18 years.

Senior dosage (ages 65 years and older)

Older adults may process this drug more slowly. A normal adult dose may cause levels of the drug to build up higher than normal in your body. Your doctor may lower your dose or give you a different dosing schedule.

Disclaimer: Our goal is to provide you with the most relevant and current information. However, because drugs affect each person differently, we cannot guarantee that this list includes all possible dosages. This information is not a substitute for medical advice. Always to speak with your doctor or pharmacist about dosages that are right for you.
Pharmacist's Advice
Healthline Pharmacist Editorial Team

Toremifene comes with serious risks if you don't take it as prescribed.

If you don't take it at all, stop taking it suddenly, or don't take it on schedule

Your cancer may progress and your condition may get worse.

If you take too much

You could have dangerous levels of the drug in your body. You may have the following symptoms:

  • hot flashes
  • vaginal bleeding
  • dizziness
  • hallucinations
  • loss of control of your body movements
  • nausea

If you think you’ve taken too much of the drug, act right away. Call your doctor or local Poison Control Center, or go to the nearest emergency room.

What to do if you miss a dose

If you forget to take your dose, take it as soon as you remember. If it’s just a few hours before the time of your next dose, then only take one dose at that time.

Never try to catch up by taking two doses at once. This could result in toxic side effects.

How to tell if the drug is working

You may be able to tell if this drug is working if you have fewer symptoms caused by your cancer. Your doctor will do tests to see how the medicine is affecting your cancer.

If it’s not possible to eliminate your cancer, toremifene may help slow its growth or reduce the symptoms caused by your cancer.

Toremifene can be a short-term or long-term drug treatment.

It’s usually continued until your cancer progresses or you feel you can’t take it any longer.

Important considerations for taking toremifene
take with or without food
Toremifene can be taken with or without food
can cut or crush the tablet
You can crush or cut the tablet
storage
Store toremifene at room temperature
See Details
refillable
Prescription is refillable
travel
Travel
See Details
Clinical monitoring
Clinical monitoring
See Details
diet
Your diet
See Details
not usually stocked
Not every pharmacy stocks this drug, so call ahead
insurance
Insurance
See Details

Store toremifene at room temperature

Keep it from 59–86°F (15–30°C).

Don’t freeze toremifene.

Keep the drug away from light and high temperature.

Keep your drugs away from areas where they could get wet, such as bathrooms. Store this drug away from moisture and damp locations.

Travel

When traveling with your medication:

  • Always carry your medication with you, such as in your carry-on bag.
  • Don’t worry about airport X-ray machines. They can’t hurt your medication.
  • You may need to show airport staff the pharmacy label for your medication. Always carry the original prescription-labeled box with you.
  • Don’t put this medication in your car’s glove compartment or leave it in the car. Be sure to avoid doing this when the weather is very hot or very cold.

Clinical monitoring

Before starting and during treatment with this drug, your doctor may check your:

  • calcium, potassium, and magnesium levels
  • liver function
  • red and white blood cell counts

Your diet

You shouldn’t drink grapefruit juice while you’re taking toremifene. Grapefruit juice can increase the amount of the drug in your body and raise your risk for side effects.

Insurance

Many insurance companies will require a prior authorization before they approve the prescription and pay for toremifene.

Are there any alternatives?

There are other drugs available to treat your condition. Some may be more suitable for you than others. Talk to your doctor about possible alternatives.

What does the pill look like?

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How Much Does toremifene Cost?

Oral tablet

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Lowest price for toremifene

Membership warehouse $1,193.09
Kroger Pharmacy $1,196.76
Target (CVS) $1,225.67
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These prices represent the lowest priced national pharmacies for toremifene on GoodRx. They may be lower than your insurance.

Show Sources

  • Fareston – toremifene citrate [package insert]. Memphis, TN: GTx, Inc.; Revised March 2011.

Content developed in collaboration with University of Illinois-Chicago, Drug Information Group

Medically reviewed by Creighton University, Center for Drug Information and Evidence-Based Practice on September 9, 2015

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.
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