Toremifene has caused very serious (possibly fatal) heart rhythm problems (QT prolongation in the EKG, torsades de pointes). Get medical help right away if any of these rare but serious side effects occur: fast/irregular heartbeat, seizures, severe dizziness, or fainting. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm. Before using toremifene, tell your doctor or pharmacist of all the drugs you take (see also Drug Interaction section) and if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).
Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using toremifene safely.Who should not take Fareston?
Toremifene is used in postmenopausal women to treat breast cancer that has spread to other parts of the body (metastatic breast cancer). It is usually used to treat cancer that needs estrogen, a female hormone, in order to grow (estrogen-receptor positive). Toremifene is a nonsteroidal antiestrogen that blocks the effects of estrogen in the breast tissue, thereby slowing or stopping the growth of cancer.
Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.
Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.
Inform your doctor right away if your condition worsens (e.g., you get new breast lumps).
See also Warning section.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if any of these unlikely but serious side effects occur: bone/joint/muscle pain or swelling, constipation, mental/mood changes (e.g., depression), trouble walking/clumsiness, swelling ankles/feet, unusual tiredness, vision changes (e.g., blurred vision, eye pain).
Toremifene may increase your risk of uterine cancer. Tell your doctor right away if you develop changes in menstrual period, unusual vaginal bleeding/discharge or pain/pressure below your "belly button" (navel).
Tell your doctor right away if any of these rare but very serious side effects occur: easy bleeding/bruising, signs of infection (e.g., fever, chills, persistent sore throat), persistent nausea/vomiting, severe abdominal/stomach pain, dark urine, yellowing eyes/skin.
Toremifene has rarely caused very serious (possibly fatal) blood clots in the lungs/legs, brain (stroke), and heart (heart attack). Seek immediate medical attention if you develop pain/swelling in the groin/calf, pain in the chest/jaw/left arm, confusion, fainting, severe sudden headache, slurred speech, sudden vision changes, shortness of breath, or weakness on one side of the body.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
See also Warning section.
Before taking toremifene, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: bone cancer (metastases), blood disorders (e.g., anemia, low platelets), diabetes, history of stroke or other blood clots (e.g., in the legs, lungs), heart disease (e.g., heart attack, irregular heartbeat), high blood pressure, liver disease, long periods of sitting or lying down (e.g., immobility such as being bedridden), uterus problems such as endometrial hyperplasia.
This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.
Notify your doctor beforehand if you will be having surgery or will be confined to a chair/bed for a long time (e.g., a long plane flight).
During pregnancy, toremifene should be used only when clearly needed. It may harm an unborn baby. If you become pregnant or think you may be pregnant, inform your doctor right away. Women of childbearing age should use reliable forms of non-hormonal birth control (such as condoms, diaphragm with spermicide) while using this medication. Discuss the use of birth control, the risks and benefits of this medication, and any other concerns about using this medication with your doctor.
It is not known if this medication passes into breast milk. Because of the possible risk to the infant, breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug include: "blood thinners" (e.g., warfarin), estrogens, "water pills" (diuretics such as hydrochlorothiazide), drugs affecting liver enzymes that remove toremifene from your body (e.g., certain anti-seizure medications such as carbamazepine/clonazepam/phenobarbital/phenytoin, rifampin).
Many drugs besides toremifene may affect the heart rhythm (QT prolongation), including amiodarone, granisetron, pimozide, procainamide, quinidine, sotalol, macrolide antibiotics (such as erythromycin), and certain quinolone antibiotics (such as levofloxacin), among others.
If overdose is suspected, contact a poison control center or emergency room right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
Do not share this medication with others.
Laboratory and/or medical tests (e.g., complete blood count, calcium levels, liver tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.
Information last revised October 2015. Copyright(c) 2015 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet