FARESTON

What it is

Fareston contains toremifene citrate equivalent to toremifene 60 mg per tablet. Toremifene is a non-steroidal triphenylethylene derivative that binds to oestrogen receptors and may exert oestrogenic, anti-oestrogenic or both activities, depending upon the duration of treatment, animal species, gender, target organ and variable selected. Toremifene binds specifically to oestrogen receptors, competitively with oestradiol, and inhibits oestrogen-induced stimulation of DNA synthesis and cell replication.

Approved indications

— First line treatment of hormone-dependent metastatic breast cancer in postmenopausal patients.

Dosing overview

The recommended dose is one tablet (60 mg) daily. Toremifene can be taken with or without food.

Key safety warnings

Changes in cardiac electrophysiology have been observed following exposure to toremifene, in the form of QT prolongation, and toremifene is contraindicated in patients with congenital or documented acquired QT prolongation, electrolyte disturbances particularly in uncorrected hypokalaemia, clinically relevant bradycardia, clinically relevant heart failure with reduced left-ventricular ejection fraction, or previous history of symptomatic arrhythmias. Fareston has been shown to prolong the QT/QTc interval on the electrocardiogram in a dose-related manner. 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 (including Torsade de pointes) and cardiac arrest. 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 occurring during the first months of treatment, with the pattern of the liver damage being predominantly hepatocellular. Gynaecological examination should be performed before treatment administration, closely looking at pre-existing endometrial abnormality, and afterwards gynaecological examination should be repeated at least once a year. Endometrial hypertrophy may develop during the treatment due to the hormonal (partial oestrogenic) effect of toremifene, and there is a risk of increased endometrial changes including hyperplasia, polyps and cancer. Anemia, leukopenia and thrombocytopenia have been reported, and red blood cell, leukocyte or platelet counts should be monitored when using Fareston.

Contraindications

Hypersensitivity to the active substance or to any of the excipients. Pregnancy. Pre-existing endometrial hyperplasia and severe hepatic failure are contraindications for long-term use of toremifene. <cite index index="1-14">Toremifene is contraindicated in patients with congenital or documented acquired QT prolongation, electrolyte disturbances particularly in uncorrected hypokalaemia, clinically relevant bradycardia, clinically relevant heart failure with reduced left-ventricular ejection fraction, or previous history of symptomatic arrhythmias.</cite> Toremifene should not be used concurrently with other drugs that prolong the QT interval.

PBS listing

Fareston 60 mg tablets are listed on the PBS with 2 items, unrestricted and restricted access, at an ex-manufacturer price of A$35.96.

Regulatory history

Fareston (toremifene citrate 60 mg tablets) was first registered on the ARTG on 6 June 1997.