Orexin Receptor Antagonist


Orexin Receptor Antagonist, Suvorexant, Belsomra, Dayvigo, Lemborexant

  • Indications
  • Preparations
  1. Belsomra (Suvorexant) 10 mg orally at bedtime
  2. Dayvigo (Lemborexant) 5 mg orally at bedtime
  • Mechanism
  1. FDA Schedule IV Agent (as with other Nonbenzodiazepine Sedative-Hypnotic agents)
  2. Orexin (hypocretin) is a Neurotransmitter that promotes wakefulness (deficiency in Narcolepsy)
  3. Blocking orexin transiently allows for sleep
  • Efficacy
  1. Similar effectiveness to other standard agents used for Insomnia (e.g. Zolpidem)
  2. Compared with Placebo, patients on Belsomra fall asleep 5-10 min faster, and stay asleep 22 min longer
  • Adverse Effects
  1. Daytime Somnolence
  2. Leg weakness (transient, rare)
  • Drug Interactions
  1. Metabolized by CYP3A4
  2. Moderate CYP3A4 Inhibitors (e.g. Verapamil)
    1. Start Belsomra at low dose (e.g. 5 mg)
  3. Strong CYP3A4 Inhibitors (e.g. Clarithromycin, Itraconazole)
    1. Avoid Belsomra with strong CYP3A4 Inhibitors
  • Disadvantages
  1. Expensive ($300/month) agent
  2. No benefit over Zolpidem (Ambien) which is $10/month at generic pricing
  • References
  1. (2015) Presc Lett 22(2):10