Fareston treats breast cancer in women who gone through menopause. May cause hot flashes.

Fareston Overview


Fareston is a prescription medication used to treat certain types of breast cancer in post-menopausal women.

Fareston belongs to a group of drugs called nonsteroidal antiestrogens. It works by blocking the activity of estrogen in the breast which stops the cancer from growing.

This medication comes in tablet form and is taken once a day, with or without food. 

Common side effects of Fareston include sweating, hot flashes, nausea, and dizziness. 

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  • Other
  • Breast Neoplasms
  • Neoplasms, Hormone-dependent

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Fareston Cautionary Labels


Uses of Fareston

Fareston is a prescription medication used to treat certain types of breast cancer in post-menopausal women.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information. 



Fareston Drug Class

Fareston is part of the drug class:

Side Effects of Fareston

Some common side effects of Fareston include:

  • sweating
  • hot flashes
  • nausea
  • dizziness
  • dry eyes

If any of these side effects are bothersome or do not go away, notify your doctor right away.

Tell your doctor right away if you experience any of these severe side effects:

  • bone, joint, or muscle pain or swelling
  • constipation
  • mental (mood) changes (such as depression or hallucinations)
  • difficulty walking or decreased coordination
  • swelling ankles, feet, lower legs, hands, face, mouth, lips, tongue, or throat
  • rash or itching
  • difficulty breathing
  • unusual tiredness
  • vision changes (such as blurred vision, eye pain)
  • fever, chills, or sore throat
  • changes in menstrual period
  • unusual vaginal bleeding or discharge
  • easy bleeding or bruising
  • severe nausea and vomiting
  • severe stomach pain
  • dark urine
  • yellowing eyes or skin
  • numbness of arm or leg
  • weakness on one side of the body
  • chest pain or jaw pain
  • irregular heartbeat
  • fainting
  • sudden, severe headache

This is not a complete list of Fareston side effects. Ask your doctor or pharmacist for more information.

Fareston Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

  • amitriptyline (Elavil)
  • antifungals such as ketoconazole (Nizoral), itraconazole (Sporanox), or voriconazole (Vfend)
  • clarithromycin (Biaxin, in Prevpac)
  • erythromycin (E.E.S., E-Mycin, Erythrocin)
  • granisetron (Kytril)
  • haloperidol (Haldol)
  • certain medications for human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS) such as atazanavir (Reyataz), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir, in Kaletra), and saquinavir (Invirase)
  • certain medications for irregular heartbeat such as amiodarone (Cordarone, Pacerone), disopyramide (Norpace), dofetilide (Tikosyn), ibutilide (Corvert), procainamide (Procanbid, Pronestyl), quinidine, and sotalol (Betapace, Betapace AF)
  • levofloxacin (Levaquin)
  • nefazodone
  • ofloxacin
  • ondansetron (Zofran)
  • telithromycin (Ketek)
  • thioridazine
  • venlafaxine (Effexor)
  • anticoagulants (''blood thinners'') such as warfarin (Coumadin)
  • carbamazepine (Epitol, Equetro, Tegretol)
  • cimetidine (Tagamet)
  • clonazepam (Klonopin)
  • dexamethasone (Decadron, Dexone)
  • diltiazem (Cardizem, Dilacor, Tiazac, others)
  • diuretics ('water pills') such as hydrochlorothiazide
  • fluvoxamine
  • phenobarbital
  • phenytoin (Dilantin, Phenytek)
  • rifabutin (Mycobutin)
  • rifampin (Rifadin, Rimactane)
  • verapamil (Calan, Covera, Isoptin, Verelan)
  • St. John's wort

This is not a complete list of Fareston drug interactions. Ask your doctor or pharmacist for more information.

Fareston Precautions

Do not use Fareston if you are allergic to any of its ingredients.

Do not use Fareston if you have long QT syndrome or low blood potassium or magnesium levels.

Fareston may make you dizzy. Do not drive or operate heavy machinery or perform any activity that requires alertness until you know how Fareston affects you.

Fareston may cause a serious heart condition called QT prolongation (irregular heart rhythm). Tell your doctor right away if you have any of the following symptoms:

  • fast, pounding, or irregular heartbeat
  • fainting spell
  • seizures

This medication can lower the number of white blood cells and platelets in your blood, increasing the risk of getting an infection and bleeding. Avoid people with infections. Tell your doctor right away if you have signs of infection including:

  • fever
  • chills
  • sore throat
  • cough

Tell your doctor if you experience unusual bleeding or bruising, or blood in the urine or stools.

You may experience bleeding from the vagina when you first start using this medication. If bleeding continues, notify your doctor.


Fareston Food Interactions

Grapefruit and grapefruit juice may interact with Fareston and lead to potentially dangerous effects. Discuss the use of grapefruit products with your doctor.

Inform MD

Before receiving Fareston, tell your doctor about all of your medical conditions including if you:

  • are allergic to any ingredient in Fareston , or any other medication
  • have long QT syndrome (a rare inherited heart condition)
  • have low blood levels of potassium or magnesium (an electrolyte imbalance)
  • have bone cancer
  • have endometrial hyperplasia (overgrowth of the lining of the uterus)
  • have irregular heartbeat
  • have heart failure
  • have liver disease
  • are pregnant or breastfeeding

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements.

Fareston and Pregnancy

Fareston is approved for use in women who have been through menopause. If you have not been through menopause you should avoid pregnancy during Fareston treatment. This medication may harm the unborn baby.

Talk to your doctor about the use of birth control while receiving this medication.

Tell your doctor right away if you become pregnant during Fareston treatments.

Fareston and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if Fareston is excreted in human breast milk or if it will harm your nursing baby.

Fareston Usage

Fareston comes as a tablet to be taken by mouth, usually once a day, with or without food. Try to take Fareston at the same time every day.

Take Fareston exactly as prescribed. Follow the directions on your prescription label carefully. Do not take more or less of it or take it more often than prescribed by your doctor.

If you forget a dose, take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take two doses at once.

Your doctor will likely order blood tests to monitor for harmful side effects.


Fareston Dosage

Take Fareston exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The recommended daily dosage of Fareston is 60 mg.

Fareston Overdose

If you take too much Fareston, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

If Fareston is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdose is suspected, seek emergency medical attention.

Other Requirements

  • Store Fareston at room temperature, between 59°F to 86°F (15°C to 30°C).
  • Keep this and all medicines out of the reach of children.

Fareston FDA Warning


Fareston has been shown to prolong the QTc interval in a dose- and concentration-related manner. Prolongation of the QT interval can result in a type of ventricular tachycardia called Torsade de pointes, which may result in syncope, seizure, and/or death. Fareston should not be prescribed to patients with congenital/acquired QT prolongation, uncorrected hypokalemia or uncorrected hypomagnesemia. Drugs known to prolong the QT interval and strong CYP3A4 inhibitors should be avoided.