Toremifene (fareston) is associated with a dose-dependent risk of QT prolongation.
Article date: February 2009
Toremifene (fareston) is an oestrogen receptor antagonist. Currently it is not widely used in the UK, but remains a licensed option to treat hormone-dependent metastatic breast cancer in postmenopausal women.
A European assessment has concluded that toremifene is associated with a dose-dependent risk of increase in QT interval, which carries a risk of serious cardiac arrhythmia. The summary of product characteristics has been updated to include new contraindications and warnings. Do not prescribe toremifene with other drugs that prolong the QT interval.