Medically Reviewed on 2/13/2023

Generic Name: suvorexant

Brand Name: Belsomra

Drug Class: Sedative/Hypnotics; Orexin Antagonists

What is suvorexant, and what is it used for?

Suvorexant is a sedative medication used to treat insomnia, characterized by difficulty in falling and/or staying asleep at night. Suvorexant promotes sleep by reducing arousal and wakefulness.

Suvorexant belongs to a class of medications known as orexin antagonists that work by blocking the activity of orexins, also known as hypocretins, chemical messengers (neurotransmitters) that regulate arousal, wakefulness, and appetite.

Orexin A and B are produced by specialized nerve cells (neurons) in the hypothalamus region of the brain. These neurons are active during wakefulness and stop their signaling during sleep. Orexin A and B activate arousal and wakefulness by binding to orexin 1 and 2 receptors, protein molecules on neuronal membranes. Suvorexant binds to orexin 1 and 2 receptors and prevents orexin A and B from binding to them and activating the wake drive.


  • Do not use suvorexant to treat patients with narcolepsy, a chronic sleep disorder that causes extreme drowsiness during the daytime.
  • Suvorexant is a central nervous system (CNS) depressant and can cause daytime drowsiness, even when used in prescribed doses. CNS depressant effects may persist in some patients for several days after discontinuing the medication.
    • Monitor patients and decrease dose or discontinue suvorexant in patients who experience daytime somnolence.
    • Caution patients to avoid activities requiring mental alertness the next day after taking the medication in the night.
    • Patients on suvorexant, particularly the elderly, are at an increased risk for falling.
    • Do not prescribe suvorexant concurrently with other CNS suppressants such as benzodiazepines, opioids, and tricyclic antidepressants. Advise patients to avoid alcohol consumption while on suvorexant therapy.
  • Suvorexant can worsen depression and cause suicidal ideation. Intentional overdose is more common in patients with depression. Evaluate the patient for risk of suicidal behavior, prescribe the lowest feasible number of tablets, and caution patients and caregivers to be alert for symptoms of worsening depression and suicidal thoughts and behavior.
  • Suvorexant use can cause complex sleep disorders such as sleep-walking, sleep-driving, and engaging in other activities while not fully awake, often with no memory of these activities later. Caution patients and caregivers to be alert and report such events, and discontinue the drug if a patient develops such behavior.
  • Explain to patients that suvorexant can cause sleep paralysis, an inability to speak or move for several minutes during the sleep-wake transition, and vivid hallucinations. The drug can also cause sudden transient muscle weakness (cataplexy) triggered by surprise or laughter.
  • Consider the effects of suvorexant on respiratory function and exercise caution when prescribing to patients with severe obstructive sleep apnea or severe chronic obstructive pulmonary disease (COPD).
  • Evaluate patients carefully before initiating suvorexant treatment for insomnia, because other physical or psychiatric disorders may cause sleep disturbances, and symptoms of these underlying conditions may emerge with the treatment. Failure of insomnia remission after 7 to 10 days of treatment may indicate the presence of other disorders. 

What are the side effects of suvorexant?

Common side effects of suvorexant include:

Less common side effects of suvorexant include:

Call your doctor immediately if you experience any of the following symptoms or serious side effects while using this drug:

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.


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What are the dosages of suvorexant?

Tablet Schedule IV

  • 5 mg
  • 10 mg
  • 15 mg
  • 20 mg



  • Indicated for insomnia characterized by difficulties with sleep onset and/or sleep maintenance
  • Recommended starting dose: 10 mg oral taken no more than once per night and within 30 minutes of going to bed, with at least 7 hours remaining before the planned time of awakening
  • Use the lowest dose effective for the patient. If 10 mg dose is well-tolerated but not effective, the dose can be increased
  • Not to exceed 20 mg once daily

Dosage Modifications

Renal impairment

  • No dosage adjustment required

Hepatic impairment

  • Mild-to-moderate: No dosage adjustment is required
  • Severe: Not recommended

Coadministration with CYP3A4 inhibitors

  • Strong: Not recommended
  • Moderate: Decrease suvorexant recommended dose to 5 mg oral at night; if tolerated but not effective, may increase the dose, not to exceed 10 mg/dose

Dosing Considerations

  • Systemic exposure increased in obese compared with nonobese patients, and in women compared with men
  • Particularly in obese women, the increased risk of exposure-related adverse effects should be considered before increasing the dose


Safety and efficacy not established


  • Suvorexant has a potential for abuse, addiction, and dependence, particularly in patients with a history of drug abuse.
  • Overdose of suvorexant can cause drowsiness and suppression of the central nervous system (CNS).
  • Suvorexant overdose is treated with general supportive and symptomatic care, including gastric lavage to eliminate the undigested drug, administration of intravenous fluids, and monitoring of vital signs.

What drugs interact with suvorexant?

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

  • Suvorexant has no listed severe interactions with other drugs.
  • Suvorexant has serious interactions with at least 53 different drugs.
  • Suvorexant has moderate interactions with at least 121 different drugs.
  • Mild interactions of suvorexant include:

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider about all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information. Check with your doctor or healthcare provider if you have any questions about the medication.

Pregnancy and breastfeeding

  • There are no adequate and well-controlled studies on the safety of suvorexant use in pregnant women. Animal reproductive studies indicate the drug may cause harm to the mother and fetus at high doses.
  • Use suvorexant with caution during pregnancy, if potential benefits outweigh potential risks to the mother and the fetus.
  • There is no information on the presence of suvorexant in breastmilk, and its effect on milk production and the breastfed infant. Suvorexant is present in animal milk and is likely also present in human breastmilk.
  • Decision to breastfeed during suvorexant therapy should be based on the importance of the drug to the mother, the health benefits of breastfeeding, and potential risks to the infant from the underlying maternal condition and drug exposure.
  • Infants exposed to suvorexant through breastmilk should be monitored for sedation.

What else should I know about suvorexant?

  • Take suvorexant exactly as prescribed. Do not increase the dosage without checking with your physician.
  • Exercise caution, suvorexant has a potential for abuse, dependence, addiction, and overdose.
  • Take suvorexant only if you can spend the entire night in bed before getting active again.
  • Suvorexant can cause daytime drowsiness. Do not drive or engage in other activities that require mental alertness for 8 hours after taking suvorexant. Avoid driving and other hazardous activities on the day after taking the drug, especially if taking 20 mg dosage.
  • Suvorexant increases the risk of falling, especially in the elderly. Exercise caution.
  • Suvorexant can cause complex sleep behaviors including sleep-walking, sleep-driving, and other activities while not fully awake. Patients and caregivers should report to the healthcare provider if such symptoms occur.
  • Suvorexant can worsen depression and cause suicidal thoughts and behavior. Report such symptoms immediately to your healthcare provider.
  • Avoid alcohol and other drugs that can depress the central nervous system when taking suvorexant, they can have additive effects.
  • Store suvorexant safely out of reach of children and any visitors.
  • In case of overdose, seek medical help immediately or contact Poison Control.

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Suvorexant is a sedative medication used to treat insomnia, characterized by difficulty in falling and/or staying asleep at night. Suvorexant promotes sleep by reducing arousal and wakefulness. Do not use suvorexant to treat patients with narcolepsy. Suvorexant can worsen depression and cause suicidal ideation. Common side effects of suvorexant include headache, drowsiness (somnolence), dizziness, abnormal dreams, upper respiratory tract infections, cough, diarrhea, and dry mouth. Consult your doctor if pregnant or breastfeeding.

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Medically Reviewed on 2/13/2023