Toremifene Side Effects

Medically reviewed by Drugs.com. Last updated on Aug 30, 2024.

Applies to toremifene: oral tablet.

Precautions

It is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects. It is important for women to have regular gynecologic check-ups while taking this medicine.

It is unlikely that a postmenopausal woman may become pregnant. But, using this medicine while you are pregnant could harm your unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test before you start using this medicine to make sure you are not pregnant. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

Contact your doctor right away if you have any changes to your heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you had a heart rhythm problem, such as QT prolongation.

Check with your doctor right away if you have pain or tenderness in the upper stomach, pale stools, dark urine, loss of appetite, nausea, vomiting, or yellow eyes or skin. These could be symptoms of a serious liver problem.

Hypercalcemia (high calcium in the blood) and tumor flare (increased size of a tumor) are more likely to occur in patients with bone problems who are taking this medicine. Check with your doctor right away if you have stomach pain, confusion, constipation, depression, dry mouth, increased urination, loss of appetite, metallic taste, muscle weakness, pain and swelling in the bones and muscles surrounding a tumor, thirst, unusual tiredness, or weight loss.

This medicine may increase your risk of having uterus problems, including endometrial cancer. Talk with your doctor if you have concerns about this.

Toremifene can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

• If you can, avoid people with infections. Check with your doctor immediately if you think you are getting an infection or if you get a fever or chills, cough or hoarseness, lower back or side pain, or painful or difficult urination.
• Check with your doctor immediately if you notice any unusual bleeding or bruising, black, tarry stools, blood in the urine or stools, or pinpoint red spots on your skin.
• Be careful when using a regular toothbrush, dental floss, or toothpick. Your medical doctor, dentist, or nurse may recommend other ways to clean your teeth and gums. Check with your medical doctor before having any dental work done.
• Do not touch your eyes or the inside of your nose unless you have just washed your hands and have not touched anything else in the meantime.
• Be careful not to cut yourself when you are using sharp objects such as a safety razor or fingernail or toenail cutters.
• Avoid contact sports or other situations where bruising or injury could occur.

This medicine may cause you to have bleeding from the vagina, especially when you first start using it. If the bleeding continues or is bothersome, check with your doctor right away.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (eg, St. John's wort) or vitamin supplements.

Common side effects of toremifene

Some side effects of toremifene may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Serious side effects of toremifene

Along with its needed effects, toremifene may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking toremifene:

For healthcare professionals

Applies to toremifene: oral tablet.

General adverse events

Adverse drug reactions are primarily due to the anti-estrogenic actions of this drug and typically occur at the beginning of treatment.^[Ref]

Cardiovascular

• Very common (10% or more): Hot flashes/flushes (35%)
• Common (1% to 10%): Myocardial infarction, arrhythmia, cardiac failure, thrombophlebitis, thrombosis
• Uncommon (0.1% to 1%): Angina pectoris
• Frequency not reported: QT/QTc interval prolongation^[Ref]

Dermatologic

• Very common (10% or more): Sweating (20%)
• Common (1% to 10%): Rash, pruritus/itching
• Uncommon (0.1% to 1%): Skin discoloration
• Rare (less than 0.1%): Dermatitis, alopecia^[Ref]

Hepatic

• Very common (10% or more): Elevated AST (19%), elevated alkaline phosphatase (19%)
• Common (1% to 10%): Elevated bilirubin
• Rare (less than 0.1%): Jaundice
• Very rare (less than 0.01%): Hepatitis^[Ref]

Gastrointestinal

• Very common (10% or more): Nausea (14%)
• Common (1% to 10%): Vomiting
• Uncommon (0.1% to 1%): Constipation^[Ref]

Genitourinary

• Very common (10% or more): Vaginal discharge/leukorrhea (13%)
• Common (1% to 10%): Vaginal/uterine bleeding
• Uncommon (0.1% to 1%): Endometrial hypertrophy
• Rare (less than 0.1%): Endometrial polyps
• Very rare (less than 0.01%): Endometrial hyperplasia^[Ref]

Ocular

• Very common (10% or more): Cataracts (10%)
• Common (1% to 10%): Dry eyes, abnormal visual fields, corneal keratopathy, glaucoma, abnormal vision/diplopia
• Uncommon (0.1% to 1%): Reversible corneal opacity (corneal verticillata/verticulata)^[Ref]

Metabolic

• Common (1% to 10%): Hypercalcemia
• Uncommon (0.1% to 1%): Anorexia, increased weight, appetite loss^[Ref]

Nervous system

• Common (1% to 10%): Dizziness, cerebrovascular accident/transient ischemic attack
• Uncommon (0.1% to 1%): Paresis, tremor, vertigo, headache
• Rare (less than 0.1%): Stiffness
• Frequency not reported: Rigors^[Ref]

Other

• Common (1% to 10%): Edema, pain, fatigue
• Uncommon (0.1% to 1%): Asthenia, chest pain^[Ref]

Psychiatric

• Common (1% to 10%): Depression
• Uncommon (0.1% to 1%): Insomnia
• Rare (less than 0.1%): Emotional lability^[Ref]

Respiratory

• Common (1% to 10%): Pulmonary embolism
• Uncommon (0.1% to 1%): Dyspnea^[Ref]

Musculoskeletal

• Uncommon (0.1% to 1%): Back pain^[Ref]

Hematologic

• Rare (less than 0.1%): Leukopenia, thrombocytopenia
• Frequency not reported: Anemia^[Ref]

Oncologic

• Very rare (less than 0.01%): Endometrial cancer
• Frequency not reported: Tumor flare^[Ref]

See also:

Further information

Toremifene side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer