Androgen Suppression Therapies: Product Information Updated Due to QT Interval Prolongation

Germany's Federal Institute for Drugs and Medical Devices (BfArM) has asked the marketing authorization holders for drugs that suppress androgens to adapt their product information. This directive follows observations of QT interval prolongation during therapy.

The affected drug substances include agonists and some antagonists of gonadotropin-releasing hormone (GnRH), such as abarelix and degarelix, as well as antiandrogens like flutamide, nilutamide, bicalutamide, and enzalutamide, and abiraterone. These medications are all used in the treatment of hormone-dependent prostate cancer to suppress androgens.

In September, the European Medicines Agency's (EMA) Pharmacovigilance Risk Assessment Committee (PRAC) reviewed spontaneous reports and literature. The committee concluded that long-term androgen suppression can lead to QT interval prolongation. Consequently, additional warnings must be included in the product information.

For patients with risk factors for QT interval prolongation or those receiving concomitant QT-prolonging therapy, a benefit-risk assessment should be performed before initiating treatment with these substances. Other drugs known to prolong the QT interval include class 1A and class III antiarrhythmics, methadone, moxifloxacin, and antipsychotics.