Generic Name: toremifene (tore-EM-i-feen)
Brand Name: Fareston
Toremifene has been shown to cause a serious type of irregular heartbeat (QT prolongation). QT prolongation can also result in another serious and sometimes fatal type of irregular heartbeat called torsades de pointes, which may also cause fainting or seizures. Do not take toremifene if you have congenital or acquired QT prolongation (long QT syndrome), or if you have low blood potassium or magnesium levels. Certain medicines may increase the risk of irregular heartbeat and should be avoided. Check with your doctor to see if any of your medicines may increase the risk of irregular heartbeat.
Toremifene is used for:
Treating breast cancer in women past menopause with estrogen-dependent tumors or unknown tumors. It may also be used for other conditions as determined by your doctor.
Toremifene is an antiestrogen. It works by blocking the effects of estrogen on certain body tissues, including breast tissue. This helps block the growth of estrogen-activated tumors.
Do NOT use toremifene if:
- you are allergic to any ingredient in toremifene
- you have a certain type of irregular heartbeat (congenital or acquired QT prolongation, long QT syndrome), or low blood potassium or magnesium levels
- you are taking clozapine, ondansetron, or quetiapine
Contact your doctor or health care provider right away if any of these apply to you.
Before using toremifene:
Some medical conditions may interact with toremifene. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
- if you are pregnant, planning to become pregnant, or are breast-feeding
- if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
- if you have allergies to medicines, foods, or other substances
- if you have bone cancer or an excess growth of the endometrium
- if you have a history of blood clots, cancer, or decreased blood platelets or white blood cells
- if you have a history of heart problems (eg, heart failure, irregular heartbeat), liver problems, or blood electrolyte problems
- if you take any medicine that may increase the risk of a certain type of irregular heartbeat (prolonged QT interval). Check with your doctor or pharmacist if you are unsure if any of your medicines may increase the risk of this type of irregular heartbeat
Some MEDICINES MAY INTERACT with toremifene. Tell your health care provider if you are taking any other medicines, especially any of the following:
- Antiarrhythmics (eg, amiodarone, dofetilide, sotalol), arsenic, astemizole, bepridil, chloroquine, cisapride, clozapine, crizotinib, dolasetron, domperidone, droperidol, granisetron, halofantrine, haloperidol, macrolide antibiotics (eg, clarithromycin, erythromycin), maprotiline, methadone, nilotinib, ondansetron, paliperidone, pentamidine, phenothiazines (eg, thioridazine), pimozide, quetiapine, quinolone antibiotics (eg, levofloxacin, ofloxacin), romidepsin, tacrolimus, terfenadine, tetrabenazine, tricyclic antidepressants (eg, amitriptyline), tyrosine kinase inhibitors (eg, dasatinib), vandetanib, vemurafenib, venlafaxine, or ziprasidone because the risk of severe and possibly fatal irregular heartbeat may be increased
- Fluorouracil because the risk of liver problems may be increased
- Thiazide diuretics (eg, hydrochlorothiazide) because the risk of high blood calcium levels may be increased
- Azole antifungals (eg, itraconazole, ketoconazole, voriconazole), mitomycin C, nefazodone, protease inhibitors (eg, boceprevir, ritonavir), or telithromycin because they may increase the risk of toremifene's side effects
- Carbamazepine, dexamethasone, hydantoins (eg, phenytoin), phenobarbital, rifamycins (eg, rifabutin, rifampin), or St. John's wort because the effectiveness of toremifene may be decreased
- Anticoagulants (eg, warfarin) or hydantoins (eg, phenytoin) because the actions and side effects of these medicines may be increased
This may not be a complete list of all interactions that may occur. Ask your health care provider if toremifene may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.
How to use toremifene:
Use toremifene as directed by your doctor. Check the label on the medicine for exact dosing instructions.
- Toremifene may be taken with or without food.
- Do not eat grapefruit or drink grapefruit juice while you use toremifene.
- If you miss a dose of toremifene, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.
Ask your health care provider any questions you may have about how to use toremifene.
Important safety information:
- Toremifene may cause dizziness or changes in vision. These effects may be worse if you take it with alcohol or certain medicines. Use toremifene with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
- If toremifene causes nausea or vomiting, ask your doctor or pharmacist about ways to minimize this effect.
- Toremifene is only indicated in women who have been through menopause. If you have not been through menopause and are able to become pregnant, use effective non-hormonal birth control (eg, condoms) while you take toremifene.
- Lab tests, including complete blood cell counts, blood electrolytes (eg, potassium, magnesium, calcium), electrocardiograms (ECGs), and liver function, may be performed to monitor your progress or to check for side effects. Be sure to keep all doctor and lab appointments.
- Toremifene is not indicated for use in CHILDREN.
- PREGNANCY and BREAST-FEEDING: Toremifene has been shown to cause harm to the fetus. If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using toremifene while you are pregnant. It is not known if toremifene is found in breast milk. If you are or will be breast-feeding while you are using toremifene, check with your doctor. Discuss any possible risks to your baby. Do not breast-feed while taking toremifene.
Possible side effects of toremifene:
All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur:
Dizziness; hot flashes; joint pain; loss of appetite; nausea; sweating; tiredness; vaginal discharge; vomiting.
Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); calf or leg pain, swelling, redness, warmth, or tenderness; change in vision; chest pain; confusion; coughing up blood; decreased coordination; depression; fainting; fever, chills, or sore throat; flushing; hallucinations; irregular heartbeat; muscle or bone pain; numbness of an arm or leg; one-sided weakness; seizures; shortness of breath; sluggishness; slurred speech; sudden, severe headache or vomiting; swelling of the hands, ankles, or feet; tremor; unusual bleeding or bruising; vaginal bleeding.
This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.
If OVERDOSE is suspected:
Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include dizziness; hallucinations; headache; hot flashes; nausea; loss of coordination; vaginal bleeding; vomiting.Proper storage of toremifene:
Store toremifene at 77 degrees F (25 degrees C). Brief storage at temperatures between 59 and 86 degrees F (15 and 30 degrees C) is permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep toremifene out of the reach of children and away from pets.
- If you have any questions about toremifene, please talk with your doctor, pharmacist, or other health care provider.
- Toremifene is to be used only by the patient for whom it is prescribed. Do not share it with other people.
- If your symptoms do not improve or if they become worse, check with your doctor.
- Check with your pharmacist about how to dispose of unused medicine.
This information should not be used to decide whether or not to take toremifene or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about toremifene. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to toremifene. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using toremifene.
Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your healthcare provider for complete information about the risks and benefits of using this medicine.