Source: European Medicines Agency (EU) Revision Year: 2019 Publisher: Orion Corporation, Orionintie 1, FI-02200, Espoo, Finland
Toremifene should not be used concurrently with other drugs that prolong the QT interval (see also section 4.5).
Gynaecological examination should be performed before treatment administration, closely looking at pre-existing endometrial abnormality. Afterwards gynaecological examination should be repeated at least once a year. Patients with additional risk of endometrial cancer, e.g. patients suffering from hypertension or diabetes, having high BMI (>30) or history of hormone replacement therapy should be closely monitored (see also section 4.8).
Anemia, leukopenia and thrombocytopenia have been reported. Red blood cell, leukocyte or platelet counts should be monitored when using Fareston.
Cases of liver injury, including elevation of liver enzymes (>10 times upper limit of normal), hepatitis and jaundice have been reported with toremifene. Most of them occurred during the first months of treatment. The pattern of the liver damage was predominantly hepatocellular.
Patients with a history of severe thromboembolic disease should generally not be treated with toremifene (see also section 4.8).
Fareston has been shown to prolong the QTc interval on the electrocardiogram in some patients in a dose-related manner. The following information regarding QT-prolongation is of special importance (for contraindications see section 4.3).
A QT clinical study with a 5-arm parallel design (placebo, moxifloxacin 400 mg, toremifene 20 mg, 80 mg, and 300 mg) has been performed in 250 male patients to characterize the effects of toremifene on the QTc interval duration. The results of this study show a clear positive effect of toremifene in the 80 mg group with mean prolongations of 21-26 ms. Regarding the 20 mg group, this effect is significant as well, according to ICH guidelines, with upper confidence interval of 10-12 ms. These results strongly suggest an important dose-dependent effect. As women tend to have a longer baseline QTc interval compared with men, they may be more sensitive to QTc-prolonging medications. Elderly patients may also be more susceptible to drug-associated effects on the QT interval.
Fareston should be used with caution in patients with ongoing proarrhythmic conditions (especially elderly patients) such as acute myocardial ischaemia or QT prolongation as this may lead to an increased risk for ventricular arrhythmias (incl. Torsade de pointes) and cardiac arrest (see also section 4.3).
If signs or symptoms that may be associated with cardiac arrhythmia occur during treatment with Fareston, treatment should be stopped and an ECG should be performed.
If the QTc interval is >500 ms, Fareston should not be used.
Patients with non-compensated cardiac insufficiency or severe angina pectoris should be closely monitored.
Hypercalcemia may occur at the beginning of toremifene treatment in patients with bone metastasis and thus these patients should be closely monitored.
There are no systematic data available from patients with labile diabetes, from patients with severely altered performance status or from patients with cardiac failure.
Fareston tablets contain lactose (28.5 mg/tablet). Patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption should not take this medicine
An additive effect on QT interval prolongation between Fareston and the following drugs and other medicinal products that may prolong the QTc interval cannot be excluded. This might lead to an increased risk of ventricular arrhythmias, including Torsade de pointes. Therefore co-administration of Fareston with any of the following medicinal products is contraindicated (see also section 4.3):
Drugs which decrease renal calcium excretion, e.g. thiazide diuretics, may increase the risk of hypercalcaemia.
Enzyme inducers, like phenobarbital, phenytoin and carbamazepine, may increase the rate of toremifene metabolism thus lowering the steady-state concentration in serum. In such cases doubling of the daily dose may be necessary.
There is a known interaction between anti-estrogens and warfarin-type anticoagulants leading to a seriously increased bleeding time. Therefore, the concomitant use of toremifene with such drugs should be avoided.
Theoretically the metabolism of toremifene is inhibited by drugs known to inhibit the CYP3A enzyme system which is reported to be responsible for its main metabolic pathways. Examples of such drugs are antifungal imidazoles (ketoconazole); other antifungal agents (itraconazole, voriconazole, posaconazole); protease inhibitors (ritonavir, nelfinavir), macrolides (clarithromycin, erythromycin, telithromycine). Concomitant use of those drugs with toremifene should be carefully considered.
There are no adequate data from the use of Fareston in pregnant women. Studies in animals have shown reproductive toxicity (see section 5.3). The potential risk for humans is unknown.
Fareston should not be used during pregnancy.
In rats, decreased body weight gain of the offspring during lactation was observed.
Fareston should not be used during lactation.
Toremifene is recommended for postmenopausal patients.
Toremifene has no influence on the ability to drive and use machines.
The most frequent adverse reactions are hot flushes, sweating, uterine bleeding, leukorrhea, fatigue, nausea, rash, itching, dizziness and depression. The reactions are usually mild and mostly due to the hormonal action of toremifene.
The frequencies of the adverse reactions are classified as follows: Very common (≥1/10), Common (≥1/100 to <1/10), Uncommon (≥1/1,000 to <1/100), Rare (≥1/10,000 to <1/1,000), Very rare (<1/10,000), Not known (cannot be estimated from the available data).
Very rare: endometrial cancer
Not known: thrombocytopenia, anaemia and leukopenia
Uncommon: loss of appetite
Common: depression
Uncommon: insomnia
Common: dizziness
Uncommon: headache
Very rare: transient corneal opacity
Rare: vertigo
Very common: hot flushes
Uncommon: thromboembolic events
Uncommon: dyspnoea
Common: nausea, vomiting
Uncommon: constipation
Rare: increase of transaminases
Very rare: jaundice
Not known: hepatitis, hepatic steatosis
Very common: sweating
Common: rash, itching
Very rare: alopecia
Common: uterine bleeding leukorrhea
Uncommon: endometrial hypertrophy
Rare: endometrial polyps
Very rare: endometrial hyperplasia
Common: fatigue, oedema
Uncommon: weight increase
Thromboembolic events include deep venous thrombosis, thrombophlebitis and pulmonary embolism (see also section 4.4).
Toremifene treatment has been associated with changes in liver enzyme levels (increases of transaminases) and in very rare occasions with more severe liver function abnormalities (jaundice).
A few cases of hypercalcaemia have been reported in patients with bone metastases at the beginning of toremifene treatment.
Endometrial hypertrophy may develop during the treatment due to the partial estrogenic effect of toremifene. There is a risk of increased endometrial changes including hyperplasia, polyps and cancer. This may be due to the underlying mechanism/estrogenic stimulation (see also section 4.4). Fareston increases the QT interval in a dose-related manner (see also section 4.4).
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system listed in Appendix V.
Not applicable.
© All content on this website, including data entry, data processing, decision support tools, "RxReasoner" logo and graphics, is the intellectual property of RxReasoner and is protected by copyright laws. Unauthorized reproduction or distribution of any part of this content without explicit written permission from RxReasoner is strictly prohibited. Any third-party content used on this site is acknowledged and utilized under fair use principles.
