What you need to know about the latest sleeping pill

A controversial sleeping pill that suppresses orexin, a key chemical promoting wakefulness, is now available on the private market in Australia.

Suvorexant (Belsomra) is the first in a new class of drugs known as orexin-receptor antagonists and is indicated for treatment of insomnia that is characterised by difficulties with sleep onset and/or maintenance.

The TGA failed to approve suvorexant in 2015, citing efficacy and safety concerns, including suicidality, abnormal sleep behaviours and next-day drowsiness affecting the ability to drive.

In clinical studies, the drug has been