What is the recommended treatment regimen for insomnia using Belsomra (suvorexant)?

Recommended Treatment Regimen for Insomnia Using Belsomra (Suvorexant)

For the treatment of insomnia, Belsomra (suvorexant) should be prescribed at a starting dose of 10 mg taken once nightly within 30 minutes of going to bed, with at least 7 hours remaining before planned awakening. 1

Dosing Algorithm

1. Initial Dosing:

   • Start with 10 mg once nightly
   • Take within 30 minutes of bedtime
   • Ensure at least 7 hours remain before planned awakening
   • Take on an empty stomach for faster onset of action

2. Dose Adjustment:

   • If 10 mg is well-tolerated but not effective after 1-2 weeks, increase to 20 mg
   • Maximum recommended dose: 20 mg once nightly
   • Do not exceed 20 mg due to increased risk of next-day impairment

3. Special Population Considerations:

   • Obese patients (especially women): Consider maintaining lower doses due to increased drug exposure 1
   • Elderly patients (≥65 years): 15 mg has shown efficacy with fewer side effects than 30 mg 2
   • Patients with hepatic impairment: Not recommended for severe hepatic impairment 1

4. Drug Interaction Adjustments:

   • With moderate CYP3A inhibitors: Reduce to 5 mg (maximum 10 mg)
   • With strong CYP3A inhibitors: Not recommended
   • With CNS depressants: Consider dose reduction of Belsomra and/or the other medication 1

Clinical Evidence and Efficacy

Belsomra is specifically indicated for sleep maintenance insomnia according to the American Academy of Sleep Medicine (AASM) guidelines 3. As an orexin receptor antagonist, it works differently than other hypnotics by blocking wake-promoting orexin signals in the brain.

Clinical trials have demonstrated:

• Improved sleep maintenance (reduced wake after sleep onset by 16-28 minutes compared to placebo)
• Modest improvement in total sleep time (10 minutes longer compared to placebo) 3
• NNT of 8 for clinically meaningful improvement on the Insomnia Severity Index 4

Safety Considerations

• Most common adverse effect: Somnolence (NNH of 13 for higher doses, 28 for lower doses) 4
• Next-day effects: May impair driving and activities requiring mental alertness, particularly at doses >20 mg 1
• Complex sleep behaviors: Discontinue immediately if sleep-walking or sleep-driving occurs 1
• Monitoring: Assess for daytime somnolence, particularly in the first week of treatment
• Contraindication: Narcolepsy 1

Important Warnings and Precautions

• CNS depressant effects may persist for several days after discontinuation
• Risk of worsening depression or suicidal ideation
• May cause sleep paralysis, hypnagogic/hypnopompic hallucinations, or cataplexy-like symptoms
• Consider effects on respiratory function in vulnerable patients 1

Advantages Over Other Hypnotics

• No evidence of rebound insomnia or withdrawal effects after 3 or 12 months of nightly use 4
• Different mechanism of action compared to benzodiazepines and Z-drugs
• Potentially lower addiction liability compared to GABA-ergic sleep medications 5

Belsomra represents a valuable option for patients with sleep maintenance insomnia who have not responded to or cannot tolerate traditional hypnotics. Its unique mechanism targeting the orexin system provides an alternative approach to managing chronic insomnia.