Belsomra (suvorexant) Side Effects, Warnings, and Drug Interactions

Belsomra (suvorexant) is a sedative/hypnotic used to treat insomnia that is caused by the delay in onset of sleep or maintaining sleep. Belsomra has a unique mechanism of action different from other sleep medications, such as benzodiazepines like diazepam (Valium). 

Belsomra causes sleep by blocking receptors in the brain called orexin receptors. Orexin A and B are brain chemicals that cause people to stay awake by binding to orexin receptors. Belsomra prevents orexin A and orexin B from causing wakefulness by blocking their attachment to orexin receptors. Reduced wakefulness means more sleep or increased ability to fall asleep.  

Common side effects of Belsomra include:

• drowsiness,
• headache,
• dizziness,
• abnormal dreams,
• cough,
• diarrhea,
• dry mouth, and
• upper respiratory tract infections.

Serious side effects of Belsomra include:

• worsening depression,
• suicidal thinking,
• abnormal thinking,
• behavioral changes,
• sleep paralysis,
• physical collapse while remaining conscious (cataplexy),
• daytime impairment, and
• sleep driving and other complex behaviors.

Drug interactions of Belsomra include alcohol, which increases the effects of Belsomra. Azole antifungals, protease inhibitors, certain antibiotics, nefazodone, and conivaptan may increase blood levels of Belsomra. 

Blood levels and effect of Belsomra may be reduced by rifampin, carbamazepine, and phenytoin. Belsomra may increase blood levels of digoxin. 

Belsomra has not been adequately studied in pregnant women. It should only be used by pregnant women if the potential benefit justifies the risk to the fetus. Belsomra passes into breast milk. Consult your doctor before breastfeeding.

Common side effects of Belsomra include:

• drowsiness,
• headache,
• dizziness,
• abnormal dreams,
• cough,
• diarrhea,
• dry mouth, and
• upper respiratory tract infections.

Serious side effects of Belsomra include:

• worsening depression,
• suicidal thinking,
• abnormal thinking,
• behavioral changes,
• sleep paralysis,
• physical collapse while remaining conscious (cataplexy),
• daytime impairment, and
• sleep driving and other complex behaviors.

Common side effects include:

• Somnolence
• Headache
• Dizziness

Other side effects include:

• Abnormal dreams
• Cough
• Diarrhea
• Dry mouth
• Upper respiratory tract infections

Other less common side effects include:

• Diarrhea
• Dry mouth
• Cough

Possible serious side effects include:

• Worsening of depression
• Suicidal thinking
• Abnormal thinking
• Behavioral changes
• Sleep paralysis
• Cataplexy (physical collapse while remaining conscious)
• Daytime impairment
• Sleep driving and other complex behaviors

Belsomra has not been adequately studied in pregnant women. It should only be used by pregnant women if the potential benefit justifies the risk to the fetus.

Combining Belsomra with alcohol increases the side effects of Belsomra.

The following drugs may increase blood levels of Belsomra significantly by blocking the breakdown of Belsomra in the liver:

• Ketoconazole,
• itraconazole (Sporanox),
• posaconazole (Noxafil),
• clarithromycin (Biaxin),
• nefazodone (Serzone),
• ritonavir (Norvir),
• saquinavir (Invirase),
• nelfinavir (Viracept),
• indinavir (crixivan),
• boceprevir (Victrelis),
• telithromycin (Ketek), and
• conivaptan (Vaprisol).

Belsomra should not be combined with these drugs and other drugs that significantly block its metabolism by liver enzymes.

The blood levels and effect of suvorexant may be reduced by rifampin, carbamazepine and phenytoin because these drugs increase the breakdown of suvorexant in the liver.

Belsomra may increase blood levels of digoxin (Lanoxin) by blocking the breakdown of digoxin.