Each week we will aim to bring out a concise email that provides 4-5 key pieces of information addressing a specific issue in clinical therapeutics.
This week: Suvorexant (Non-PBS) – Orexin Receptor Antagonist for Insomnia
Eshwin Prasad, Clinical Pharmacist, Ward MM
Suvorexant is the new drug for treatment of chronic insomnia, available as Belsomra® brand. It is an orexin receptor antagonist that blocks binding of wake promoting orexin A and B neuropeptides, diminishing wake-promoting signalling. This allows the body’s sleep system to take over.
Dosing of Suvorexant
Age < 65 yrs – 20mg at night
Age > 65yrs – 15mg at night
Take within 30 mins of going to bed
With at least 7 hours remaining before planned time of awakening.
Avoid use with drugs that are inhibitors of CYP3A4, strong inducers of CYP3A4, CNS depressants and alcohol.
- Maybe useful for sleep-maintenance insomnia, however benefits for sleep onset insomnia appears uncertain.
- Following initiation, continuation should be re-evaluated after three months.
- Report adverse effects or drug interactions – new drug.
- Behaviour changes, abnormal thinking – stop suvorexant – people with neurological and psychiatric conditions were excluded from the trial.
- Somnolence and headache are common adverse effects.
- Abnormal dreams, sleep paralysis, sleep walking, suicidal ideation and hallucinations are also listed adverse effects.
- Unclear on whether rebound insomnia, dependence or withdrawal effects can occur.
Please consider these issues when preparing or interpreting RMMR reports or education sessions. Contributions of content or suggested topics are welcome and should be sent directly to firstname.lastname@example.org.