Belsomra is the first orexin receptor antagonist approved for the treatment of insomnia. The mechanism by which it exerts its therapeutic effect in insomnia is presumed to be through antagonism of orexin receptors. Blocking the binding of wake-promoting neuropeptides orexin A and orexin B to receptors OX1R and OX2R is thought to suppress wake drive.
Generic Name and Formulations: Suvorexant 5mg, 10mg, 15mg, 20mg; tabs.
Company: Merck & Co., Inc.
Therapeutic Use: Sleep-wake disorders
Indications for BELSOMRA: Treatment of insomnia characterized by difficulties with sleep onset and/or sleep maintenance.
Adult: Use lowest effective dose. Take within 30 mins of bedtime if able to get full night’s sleep (≥7hrs) before awakening. 10mg once per night; may increase if ineffective; max 20mg once daily. Concomitant moderate CYP3A inhibitors: 5mg once daily; max 10mg once daily. Effect may be delayed if taken with or soon after a meal.
Children: Not established.
Pharmacological Class: Orexin receptor antagonist.
Warnings/Precautions: Monitor for somnolence and CNS depression; discontinue or reduce dose if daytime somnolence develops. Risk of next-day impairment (including impaired driving). Monitor for worsening insomnia or abnormal thinking and behavioral changes. Consider discontinuing if any complex sleep behaviors develop. Depression. Monitor for suicidal ideation. Compromised respiratory function (eg, COPD, obstructive sleep apnea). Increased risk of exposure-related effects in obese women. Reevaluate if unresponsive after 7–10 days of treatment. Severe hepatic impairment: not recommended. Drug or alcohol abusers. Pregnancy (Cat.C). Nursing mothers.
Interactions: Avoid alcohol. Potentiates CNS depression with other CNS depressants (eg, benzodiazepines, opioids, tricyclic antidepressants, alcohol); may need to adjust doses. Concomitant strong CYP3A inhibitors (eg, ketoconazole, itraconazole, posaconazole, clarithromycin, nefazodone, ritonavir, saquinavir, nelfinavir, indinavir, boceprevir, telaprevir, telithromycin, conivaptan): not recommended. Concomitant moderate CYP3A inhibitors (eg, amprenavir, aprepitant, atazanavir, ciprofloxacin, diltiazem, erythromycin, fluconazole, fosamprenavir, grapefruit juice, imatinib, verapamil); use reduced dose (see Adults). May be antagonized by strong CYP3A inducers (eg, rifampin, carbamazepine, phenytoin). Monitor digoxin.
Adverse Reactions: Somnolence, headache, dizziness; CNS depression, daytime impairment, complex sleep-related behaviors (eg, sleep-driving), sleep paralysis, hallucinations, cataplexy-like symptoms.
Generic Availability: NO
How Supplied: Blisters—30