Drug information of Suvorexant


Drug group:

This medication is used to treat a certain sleep problem (insomnia). It may help you fall asleep and stay asleep longer, so you can get a better night's rest. Suvorexant belongs to a class of drugs known as sedative-hypnotics.

Mechanism of effect

Suvorexant exerts its therapeutic effect in insomnia through antagonism of orexin receptors. The orexin neuropeptide signaling system is a central promoter of wakefulness. Blocking the binding of wake-promoting neuropeptides orexin A and orexin B to receptors orexin receptor type 1 (OX1) and orexin receptor type 2 (OX2) is thought to suppress wake drive. Animal studies report the binding affinities for OX1 (0.55 nM) and OX2 (0.35 nM).


The bioavailability of suvorexant is at 82%. It is highly protein-bound. Food delays the time to max concentration. The primary route of elimination is through the feces, with approximately 66% of radiolabeled dose recovered in the feces compared to 23% in the urine. The elimination half-life is reported to be 12 hours.

Drug indications

Suvorexant is used for the treatment of insomnia, characterized by difficulties with sleep onset and/or sleep maintenance.

It is unclear how the medication compares to others used for insomnia as no comparisons have been done. It is also unclear if this medication is safe among people with a history of addiction, as they were excluded from the clinical trials of suvorexant.


Indicated for insomnia characterized by difficulties with sleep onset and/or sleep maintenance

Recommended starting dose: 10 mg PO taken no more than once per night and within 30 minutes of going to bed, with at least 7 hr 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


Side effects

  • Sleepiness or unusual drowsiness
  • Unusual or abnormal dreams
  • Changes in behavior
  • discouragement
  • fear or nervousness
  • feeling sad or empty
  • irritability
  • lack of appetite
  • loss of interest or pleasure
  • loss of memory
  • problems with memory
  • seeing, hearing, or feeling things that are not there
  • temporary inability to move or talk for up to several minutes while you are going to sleep or wake up
  • temporary weakness in your legs
  • thoughts of killing oneself
  • tiredness
  • trouble concentrating

Suvorexant is not recommended if people are also taking medications that strongly inhibit the liver enzyme CYP3A like itraconazole, lopinavir/ritonavir, clarithromycin, ritonavir, ketoconazole, indinavir/ritonavir, or conivaptan. If suvorexant is used with a medication that moderately inhibits the liver enzyme CYP3A, like verapamil, erythromycin, diltiazem, or dronedarone, it is recommended that the dose of suvorexant be adjusted.



  • Can impair daytime wakefulness; CNS depressant effects can last for up to several days after discontinuation
  • Can impair driving skills and may increase the risk of falling asleep while driving
  • Patients should not use suvorexant if they drank alcohol that evening or before bed; coadministration with other CNS depressants (eg, benzodiazepines, opioids, tricyclic antidepressants, alcohol) increases the risk of CNS depression
  • Dosage adjustments of suvorexant and concomitant CNS depressants may be necessary when administered together because of potentially additive effects
  • Use with other drugs to treat insomnia is not recommended
  • Risk of next-day impairment, including impaired driving, is increased if taken with less than a full night of sleep remaining, if a higher than the recommended dose is taken, if coadministered with other CNS depressants, or if coadministered with other drugs that increase suvorexant blood levels
  • Caution patients taking 20 mg to refrain from next-day driving and other activities requiring full mental alertness
  • Reevaluate patients for comorbid conditions if insomnia persists after 7-10 days of treatment
  • Cognitive and behavioral changes (eg, amnesia, anxiety, hallucinations, and other neuropsychiatric symptoms) reported with hypnotics; “sleep driving” and other complex behaviors (eg, preparing and eating food, making phone calls, or having sex), with amnesia for the event, have been reported; discontinue therapy immediately if a patient experiences a complex sleep behavior
  • The use of alcohol and other CNS depressants may increase the risk of cognitive changes listed above; discontinuation should be strongly considered

Points of recommendation

Read the Medication Guide provided by your pharmacist before you start taking suvorexant and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

Take suvorexant by mouth as directed by your doctor, usually 30 minutes before you get into bed. This medication can be taken with or without food, but it may take longer to work if you take it with or right after a meal.

The dosage is based on your medical condition, response to treatment, and other medications you may be taking. Be sure to tell your doctor and pharmacist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

Do not take a dose of this drug unless you have time for a full night's sleep of at least 7 hours. If you have to wake up before that, you may have some memory loss and may have trouble safely doing any activity that requires alertness, such as driving or operating machinery. (See also Precautions section.)

Do not increase your dose, take it more often, or use it for longer than prescribed. Your condition will not improve any faster, and your risk of side effects will increase.

Do not take this medication with alcohol, or if you have had alcohol that day, especially in the evening before bed. Also, do not take this medication with other drugs to help you sleep.

When this medication is used for a long time, it may not work as well. Talk with your doctor if this medication stops working well.

Though it helps many people, this medication may sometimes cause addiction. This risk may be higher if you have a substance use disorder (such as overuse of or addiction to drugs/alcohol). Take this medication exactly as prescribed to lower the risk of addiction. Ask your doctor or pharmacist for more details.

Tell your doctor if your condition persists after 7 to 10 days, or if it worsens.

Pregnancy level

group C

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