Dosage Forms
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Tablet, Oral:
Belsomra: 5 mg
Belsomra: 10 mg [contains fd&c blue #1 aluminum lake]
Belsomra: 15 mg, 20 mg
Pharmacology
Mechanism of Action
Suvorexant blocks the binding of wake-promoting neuropeptides orexin A and orexin B to receptors OX1R and OX2R, which is thought to suppress wake drive. Antagonism of orexin receptors may also underlie potential adverse effects such as signs of narcolepsy/cataplexy.
Pharmacokinetics/Pharmacodynamics
Absorption
Decreased at higher doses
Distribution
Vd: ~49 L
Metabolism
Primarily hepatic by CYP3A with a minor contribution from CYP2C19; the hydroxy-suvorexant metabolite is inactive.
Excretion
Feces (~66%); urine (~23%)
Onset of Action
~30 minutes
Time to Peak
2 hours (range: 30 minutes to 6 hours); Delayed approximately 1.5 hours when administered with a meal.
Half-Life Elimination
~12 hours; Half-life terminal: ~15 hours (healthy subjects, range: 10 to 22 hours), ~19 hours (moderate hepatic disease, range: 11 to 49 hours)
Protein Binding
>99%
Use in Specific Populations
Special Populations: Hepatic Function Impairment
The apparent terminal half-life of suvorexant increased from ~15 hours (range: 10 to 22 hours) in healthy subjects to ~19 hours (range: 11 to 49 hours) in patients with moderate hepatic insufficiency.
Special Populations: Gender
In females, the AUC and Cmax increased by 17% and 9%, respectively, following administration of suvorexant 40 mg. The average concentration 9 hours after dosing is 5% higher for females across the dose range studied (10 to 40 mg).
Special Populations Note
Obesity: The AUC and Cmax increases by 31% and 17%, respectively. The average concentration ~9 hours after a 20 mg dose is 15% higher in obese patients (BMI >30 kg/m2) relative to those with a normal BMI (BMI ≤25 kg/m2). In obese females, the AUC and Cmax increase by 46% and 25%, respectively.
Use: Labeled Indications
Insomnia: Treatment of insomnia characterized by difficulties with sleep onset and/or sleep maintenance.
Contraindications
Narcolepsy.
Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to suvorexant or any component of the formulation.
Dosage and Administration
Dosing: Adult
Insomnia: Oral: Note: Use the lowest effective dose for the patient. Usual dose: 10 mg once daily within 30 minutes of bedtime; may increase to a maximum of 20 mg once daily if the 10 mg dose is well tolerated but not effective. Maximum daily dose: 20 mg
Dosage adjustment for concomitant therapy:
Moderate CYP3A inhibitors (eg, amprenavir, aprepitant, atazanavir, ciprofloxacin, diltiazem, erythromycin, fluconazole, fosamprenavir, grapefruit juice, imatinib, verapamil): Usual dose: 5 mg once daily; maximum daily dose: 10 mg
Strong CYP3A inhibitors (eg, ketoconazole, itraconazole, posaconazole, clarithromycin, nefazodone, ritonavir, saquinavir, nelfinavir, indinavir, boceprevir, telaprevir, telithromycin, conivaptan): Use of suvorexant is not recommended.
CNS depressants: Dosage adjustment of suvorexant and/or the other CNS depressant may be necessary.
Dosing: Geriatric
Refer to adult dosing.
Dosing: Obesity
Consider the increased risk of exposure-related adverse effects in obese women before increasing the dose.
Administration
Oral: Administer within 30 minutes of bedtime with at least 7 hours remaining before planned time of awakening. Onset is delayed with food; do not administer with or immediately after a meal.
Dietary Considerations
For faster sleep onset, do no administer with (or immediately after) a meal.
Storage
Store at 20°C to 25°C (68°F to 77°F); excursions are permitted between 15°C and 30°C (59°F and 86°F). Protect from light and moisture.
Drug Interactions
Alcohol (Ethyl): May enhance the CNS depressant effect of Suvorexant. Avoid combination
Alizapride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination
Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification
Bosentan: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Bromopride: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Bromperidol: May enhance the CNS depressant effect of CNS Depressants. Avoid combination
Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Consider therapy modification
Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Chlormethiazole: May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Consider therapy modification
Chlorphenesin Carbamate: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy
Clofazimine: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy
CNS Depressants: May enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification
Conivaptan: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination
CYP3A4 Inducers (Moderate): May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
CYP3A4 Inducers (Strong): May increase the metabolism of CYP3A4 Substrates (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Consider therapy modification
CYP3A4 Inhibitors (Moderate): May increase the serum concentration of Suvorexant. Management: The recommended dose of suvorexant is 5 mg daily in patients receiving a moderate CYP3A4 inhibitor. The dose can be increased to 10 mg daily (maximum dose) if necessary for efficacy. Consider therapy modification
CYP3A4 Inhibitors (Strong): May increase the serum concentration of Suvorexant. Avoid combination
Dabrafenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Seek alternatives to the CYP3A4 substrate when possible. If concomitant therapy cannot be avoided, monitor clinical effects of the substrate closely (particularly therapeutic effects). Consider therapy modification
Deferasirox: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Dimethindene (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Consider therapy modification
Enzalutamide: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Concurrent use of enzalutamide with CYP3A4 substrates that have a narrow therapeutic index should be avoided. Use of enzalutamide and any other CYP3A4 substrate should be performed with caution and close monitoring. Consider therapy modification
Erdafitinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Erdafitinib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy
Flunitrazepam: CNS Depressants may enhance the CNS depressant effect of Flunitrazepam. Consider therapy modification
Fosaprepitant: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy
Fusidic Acid (Systemic): May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination
HYDROcodone: CNS Depressants may enhance the CNS depressant effect of HYDROcodone. Management: Avoid concomitant use of hydrocodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
Idelalisib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Avoid combination
Ivosidenib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy
Larotrectinib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy
Lemborexant: May enhance the CNS depressant effect of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Consider therapy modification
Lofexidine: May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs. Monitor therapy
Lorlatinib: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Avoid concurrent use of lorlatinib with any CYP3A4 substrates for which a minimal decrease in serum concentrations of the CYP3A4 substrate could lead to therapeutic failure and serious clinical consequences. Consider therapy modification
Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Melatonin: May enhance the sedative effect of Hypnotics (Nonbenzodiazepine). Monitor therapy
Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification
MetyroSINE: CNS Depressants may enhance the sedative effect of MetyroSINE. Monitor therapy
Minocycline (Systemic): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Mitotane: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Management: Doses of CYP3A4 substrates may need to be adjusted substantially when used in patients being treated with mitotane. Consider therapy modification
Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination
Oxomemazine: May enhance the CNS depressant effect of CNS Depressants. Avoid combination
OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
Palbociclib: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy
Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination
Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification
Piribedil: CNS Depressants may enhance the CNS depressant effect of Piribedil. Monitor therapy
Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy
ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy
Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy
Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy
Sarilumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy
Siltuximab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Simeprevir: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Monitor therapy
Sodium Oxybate: Hypnotics (Nonbenzodiazepine) may enhance the CNS depressant effect of Sodium Oxybate. Avoid combination
Stiripentol: May increase the serum concentration of CYP3A4 Substrates (High risk with Inhibitors). Management: Use of stiripentol with CYP3A4 substrates that are considered to have a narrow therapeutic index should be avoided due to the increased risk for adverse effects and toxicity. Any CYP3A4 substrate used with stiripentol requires closer monitoring. Consider therapy modification
Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Consider therapy modification
Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Tetrahydrocannabinol and Cannabidiol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy
Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination
Tocilizumab: May decrease the serum concentration of CYP3A4 Substrates (High risk with Inducers). Monitor therapy
Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification
Adverse Reactions
>10%: Central nervous system: Drowsiness (2% to 12%; more common in females)
1% to 10%:
Central nervous system: Headache (7%; more common in females), dizziness (3%), abnormal dreams (2%; more common in females)
Gastrointestinal: Diarrhea (2%), xerostomia (2%; more common in females)
Respiratory: Cough (2%; more common in females), upper respiratory tract infection (2%; more common in females)
Frequency not defined:
Central nervous system: Abnormal behavior, abnormality in thinking, amnesia, behavioral changes, cataplexy (mild; with or without triggering event), central nervous system depression, daytime sedation, exacerbation of depression, hallucination (including hypnagogic and hypnopompic), sleep driving, sleep paralysis, suicidal ideation
Endocrine & metabolic: Increased serum cholesterol
Neuromuscular & skeletal: Lower extremity weakness (cataplexy-like symptoms)
<1%, postmarketing, and/or case reports: Anxiety, palpitations, psychomotor agitation, tachycardia
Warnings/Precautions
Concerns related to adverse effects:
- Abnormal thinking/behavioral changes: Hypnotics have been associated with abnormal thinking and behavior changes (eg, amnesia, anxiety, hallucinations).
- CNS depression: May cause CNS depression impairing physical and mental capabilities; patients must be cautioned about performing tasks which require mental alertness (operating machinery or driving). Suvorexant should only be administered when the patient is able to stay in bed a full night (≥7 hours) before being active again. Discontinue or decrease the dose in patients who drive if daytime somnolence occurs.
- REM sleep effects: Sleep paralysis (inability to move or speak for up to several minutes during sleep-wake transitions), hypnagogic/hypnopompic hallucinations, and mild cataplexy may occur. Cataplexy symptoms may include periods of leg weakness lasting from seconds to a few minutes, can occur both at night and during the day, and may not be associated with a triggering event (eg, laughter, surprise).
- Sleep-related activities: An increased risk for hazardous sleep-related activities such as sleep-driving; cooking and eating food, making phone calls, or having sex while asleep have also been noted. Discontinue treatment in patients who report any sleep-related episodes.
Disease-related concerns:
- Depression: Use with caution in patients with depression; worsening of depression, including suicide or suicidal ideation has been reported with the use of hypnotics. Intentional overdose may be an issue in this population. The minimum dose that will effectively treat the individual patient should be used. Prescriptions should be written for the smallest quantity consistent with good patient care.
- Drug abuse: Use with caution in patients with a history of drug dependence. Risk of abuse is increased with prolonged use of suvorexant, in patients with a history of drug abuse, or those who use suvorexant in combination with alcohol or other abused drugs.
- Hepatic impairment: Use is not recommended in patients with severe hepatic impairment (has not been studied).
- Respiratory disease: Use with caution in patients with respiratory compromise, COPD, or sleep apnea.
Concurrent drug therapy issues:
- Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
Special populations:
- Female patients: Exposure is increased in females compared to males. Consider the increased risk of exposure-related adverse effects, particularly in obese females, before increasing the dose.
- Obese patients: Exposure is increased in obese compared to nonobese patients. Consider the increased risk of exposure-related adverse effects, particularly in obese females, before increasing the dose.
Other warnings/precautions:
- Appropriate use: Symptomatic treatment of insomnia should be initiated only after careful evaluation of potential causes of sleep disturbance. Failure of sleep disturbance to resolve after 7 to 10 days may indicate psychiatric and/or medical illness.
Monitoring Parameters
Daytime alertness; respiratory rate; behavior profile; tolerance, abuse, dependence
Pregnancy
Pregnancy Risk Factor
C
Pregnancy Considerations
Adverse events have been observed in some animal reproduction studies.
Patient Education
What is this drug used for?
- It is used to treat sleep problems.
Frequently reported side effects of this drug
- Fatigue
- Headache
Other side effects of this drug: Talk with your doctor right away if you have any of these signs of:
- Depression like thoughts of suicide, anxiety, emotional instability, or confusion.
- Behavioral changes
- Confusion
- Sensing things that seem real but are not
- Trouble with memory
- Trouble moving
- Trouble speaking
- Muscle weakness
- Signs of a significant reaction like wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat.
Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.
Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about this medicine. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not specific medical advice and does not replace information you receive from the healthcare provider. You must talk with the healthcare provider for complete information about the risks and benefits of using this medicine.
