Belsomra (Suvorexant): Uses, Dose, MOA, Side effects

Brand Name: Belsomra

Drug Name: Suvorexant

Blesomra Drug Class: Hypnotic, Orexin receptor inhibitor

FDA Approval date: 13th August 2014 [Ref]

Primary Indications: Insomnia

Manufacturer: Merck and Co

Orexin inhibitors used for the treatment of Insomnia, other than Belsomra include:

• Dayvigo (Lemborexant)
• Daridorexant (Quviviq)

Belsomra (Suvorexant) Uses:

Belsomra is an FDA-approved drug for the treatment of insomnia. It is used for treating people who have difficulty falling asleep or those who have difficulty maintaining sleep.

Compared to other sleep medicines, Belsomra is safe as it does not have significant side effects. It does not cause next-day drowsiness as much as other sleep medications.

It is also considered safer than benzodiazepines in aged people who may develop mental confusion, frequent falls, and impairment of thinking abilities.

It is categorized as a Scheduled IV controlled substance because of its addictive potential and dependence.

Belsomra (Suvorexant) Dose:

It is taken in a dose of 10 mg once daily at night, just before going to bed or within half an hour of going to bed. If the 10 mg is well tolerated but not effective, the dose may be increased to 20 mg once daily at bedtime.

The time-to-peak effect may be slowed if it is taken just after a meal. In addition, obese women are more at risk of developing side effects as the drug’s exposure is greater in women and obese individuals.

Patients who are on other sleep medicines should consider avoiding it or starting it with the smallest dose.

Those patients who are using strong CYP3A inhibitors should also avoid this drug. The dose should be reduced to 5 mg (and a maximum of 10 mg) in patients who are on moderate CYP3A inhibitors.

Belsomra (Suvorexant) Contraindications and Warnings:

It should be avoided by patients who have narcolepsy, a condition when the person is sleepy during the daytime and has a disturbed sleep cycle.

Warnings:

• CNS depression:

Suvorexant is a sleep-inducing drug that may be associated with drowsiness and sleepiness during the daytime.

Individuals taking it are advised to avoid driving or performing tasks that may be risky such as operating heavy machinery.

Some patients may have persistent sleepiness for days after they stop Suvorexant, especially obese people and women.

These effects are particularly a problem when concomitant alcohol or other CNS-depressant is taken.

Co-administration with drugs that increase blood levels or taking it with insufficient sleep time or a higher than recommended dose can increase the risk of impairment. It is not recommended to combine it with other sleeping pills

• Depression and suicidal risks:

In clinical studies, patients taking BELSOMRA showed an increased risk of suicidal ideation, which was found to be dose-dependent.

Therefore, it is essential to promptly assess patients for any signs of suicidal thoughts or new behavioral changes.

Patients with depression, who are primarily being treated with sedative-hypnotics like BELSOMRA, may experience worsening depression, and suicidal thoughts, and even engage in suicidal actions, including completed suicides.

Protective measures may be necessary for these patients, as drug overdose is common in this high-risk group. It is recommended to prescribe the lowest possible number of tablets at a time. Any new concerning behavioral signs or symptoms should be immediately evaluated.

• Abnormal sleep behaviors:

Suvorexant is a sleeping medicine. Some people may develop abnormal sleeping habits while using Suvorexant, including walking, driving, and engaging in activities such as gambling while asleep.

These complex sleeping behaviors can happen at any time during the treatment period. It may occur after the first dose or later during the treatment.

Concomitant use of alcohol and CNS depressants should be avoided. Any person who reports such side effects should be asked to discontinue the drug.

• Sleep paralysis and Cataplexy:

The use of BELSOMRA can lead to sleep paralysis, where individuals are temporarily unable to move or speak during transitions between sleep and wakefulness.

Hypnagogic and hypnopompic hallucinations, characterized by vivid and disturbing perceptions, are also possible. Prescribers should inform patients about these effects.

BELSOMRA can also cause symptoms similar to mild cataplexy, including brief episodes of leg weakness that may occur at any time without a specific trigger. The risk of these symptoms increases as the dose is increased.

• Respiratory Depression:

Although Suvorexant has not been studied in patients with COPD, ILD, or other respiratory conditions, it should be avoided because of the risk of respiratory depression.

Belsomra side effects:

The most common side effects are:

• Somnolence or sleepiness (7% of the patients reported daytime somnolence vs 3% in the placebo group). Women and obese people were more likely to develop somnolence.
• Other side effects are given below, however, women were twice as likely than men to develop headaches, cough, respiratory tract infection, abnormal dreams, and dry mouth.

Gastrointestinal side effects:

• Diarrhea
• Dry mouth

CNS side effects:

• Headache
• Sleepiness
• Dizziness
• Abnormal dreams
• Anxiety
• Hyperactivity

Chest-related side effects:

• Cough and respiratory tract infections

Cardiac side effects:

• Palpitations
• Increased heart rate

Belsomra (Suvorexant) MOA (Mechanism of action:

Suvorexant has a different mechanism of action than most sleeping pills. It inhibits the waking signals transmitted by Orexin neuropeptides via its receptors in the reticular activating system of the brain.

It blocks both Orexin A and Orexin B receptors (OX1R and OX2R) and blocks the signals responsible for waking a person.

Effect on QT interval: It has no significant effect on the QT interval in the usual recommended doses.

Bioavailability: 82%

The mean time to reach peak plasma concentration after it is administered in a fasting state is 2 hours.

Effect of food: Food may impair and delay its absorption by up to 1.5 hours.

Elimination from the body: It is eliminated by metabolism mainly via CYP3A and to a lesser extent by CYP2C19.

Excretion: It is primarily excreted via feces (66%) and urine (33%).