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Toremifene Side Effects

Medically reviewed by Last updated on Dec 28, 2022.

Applies to toremifene: oral tablet.


Oral route (Tablet)

Toremifene prolongs the QTc interval in a dose- and concentration-related manner and may cause a type of ventricular tachycardia called Torsade de pointes. This could result in syncope, seizures, and/or death. Toremifene 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.

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:

Less common

  • Anxiety
  • arm, back, or jaw pain
  • blurred vision
  • change in how much and how often you urinate
  • change in vaginal discharge
  • changes in skin color
  • changes in vision
  • changes in weight
  • chest pain, discomfort, tightness, or heaviness
  • confusion
  • constipation
  • cough
  • depression
  • dilated neck veins
  • dizziness, lightheadedness
  • dry mouth
  • fainting
  • fast, slow, or irregular heartbeat
  • inability to speak, incoherent speech
  • irregular breathing
  • loss of appetite
  • metallic taste in the tongue
  • muscle weakness
  • nausea
  • pain or discomfort in the arms, jaw, back, or neck
  • pain or feeling of pressure in the pelvis
  • pain, tenderness, or swelling of the foot or leg
  • seizures
  • severe or sudden headache
  • stomach pain
  • sweating
  • swelling of the face, fingers, feet, or lower legs
  • temporary blindness
  • tenderness, pain, swelling, warmth, skin discoloration, prominent superficial veins over the affected area
  • thirst
  • troubled breathing
  • unusual tiredness or weakness
  • vaginal bleeding
  • vomiting
  • weakness in the arm and or leg on one side of the body, sudden and severe

Incidence not known

  • Black, tarry stools
  • bleeding gums
  • blood in the urine or stools
  • chills
  • clay-colored stools
  • dark urine
  • fever
  • itching
  • painful or difficult urination
  • pinpoint red spots on the skin
  • rash
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • swollen glands
  • unpleasant breath odor
  • unusual bleeding or bruising
  • vomiting of blood
  • yellow eyes or skin

Other 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:

More common

  • Blindness
  • decreased vision
  • dry eyes
  • feeling of warmth
  • redness of the face, neck, arms, and occasionally, the upper chest
  • sudden sweating
  • sweating

Less common

  • Bone pain
  • changes in vision
  • double vision
  • eye pain
  • tearing

Incidence not known

  • Blistering, crusting, irritation, itching, or reddening of the skin
  • cracked, dry, or scaly skin
  • depression
  • difficulty having a bowel movement
  • feeling of constant movement of self or surroundings
  • feeling unusually cold
  • hair loss
  • lack or loss of strength
  • partial or slight paralysis
  • sensation of spinning
  • shakiness in the legs, arms, hands, or feet
  • thinning of the hair

For Healthcare Professionals

Applies to toremifene: oral tablet.


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


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]


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]


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]


Very common (10% or more): Nausea (14%)

Common (1% to 10%): Vomiting

Uncommon (0.1% to 1%): Constipation[Ref]


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]


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]


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]


Common (1% to 10%): Edema, pain, fatigue

Uncommon (0.1% to 1%): Asthenia, chest pain[Ref]


Common (1% to 10%): Depression

Uncommon (0.1% to 1%): Insomnia

Rare (less than 0.1%): Emotional lability[Ref]


Common (1% to 10%): Pulmonary embolism

Uncommon (0.1% to 1%): Dyspnea[Ref]


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


Rare (less than 0.1%): Leukopenia, thrombocytopenia

Frequency not reported: Anemia[Ref]


Very rare (less than 0.01%): Endometrial cancer

Frequency not reported: Tumor flare[Ref]


1. Product Information. Fareston (toremifene). Schering Corporation. 2001.

2. Cerner Multum, Inc. UK Summary of Product Characteristics.

3. Cerner Multum, Inc. Australian Product Information.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.