What is Suvorexant used for?

Introduction to Suvorexant

Suvorexant, marketed under the trade name Belsomra, is a relatively new pharmacological option in the treatment of insomnia characterized by difficulties with sleep onset and/or sleep maintenance. The drug was developed by Merck & Co., a prominent pharmaceutical company. Suvorexant belongs to a class of medications known as orexin receptor antagonists. Unlike traditional sleep aids that often target the GABAergic system, Suvorexant works by inhibiting the action of orexin neuropeptides, which play a crucial role in wakefulness and arousal.

The drug was approved by the U.S. Food and Drug Administration (FDA) in 2014 and has since garnered interest for its novel mechanism of action. Clinical studies have shown that Suvorexant can be effective in promoting sleep, leading to its prescription for adults who have difficulty falling asleep or staying asleep. Research institutions continue to explore the full potential of Suvorexant, including its long-term safety and efficacy, as well as its impact on specific patient populations such as the elderly or those with comorbid psychiatric conditions.

Suvorexant Mechanism of Action

Suvorexant exerts its effects by targeting the orexin system, which is involved in regulating the sleep-wake cycle. Orexins, also known as hypocretins, are neuropeptides produced in the hypothalamus that promote wakefulness and inhibit REM (rapid eye movement) sleep. There are two types of orexin receptors: OX1R and OX2R. Suvorexant is a dual orexin receptor antagonist (DORA), meaning it blocks both OX1R and OX2R. By inhibiting these receptors, Suvorexant reduces the wake-promoting signals in the brain, thereby facilitating the onset and maintenance of sleep.

The selective nature of Suvorexant's action is a significant departure from traditional sleep medications like benzodiazepines and non-benzodiazepine hypnotics, which generally enhance the activity of GABA, the primary inhibitory neurotransmitter in the central nervous system. By targeting the orexin system specifically, Suvorexant aims to mitigate risks such as dependency, tolerance, and the next-day residual effects commonly associated with GABAergic sleep aids.

How to Use Suvorexant

Suvorexant is administered orally, typically in tablet form. The advised dosage for most adults is 10 mg, taken within 30 minutes of going to bed. If the 10 mg dose is well-tolerated but not sufficiently effective, the dosage may be increased to a maximum of 20 mg, as per a healthcare provider's recommendation. It is essential to take Suvorexant no more than once per night and only if there are at least seven hours available for sleep.

The onset of action for Suvorexant generally occurs within 30 minutes to an hour after ingestion. It is recommended that the medication be taken on an empty stomach, as food can delay its absorption and thereby prolong the time it takes to feel its effects. The pharmacokinetics of Suvorexant indicates a half-life of approximately 12 hours, meaning that it stays in the body long enough to help maintain sleep through the night but is generally cleared by the next day.

What is Suvorexant Side Effects

Like all medications, Suvorexant is associated with a range of possible side effects. Common side effects include somnolence, headache, dizziness, and abnormal dreams. Less frequently, patients may experience symptoms such as sleep paralysis, hypnagogic hallucinations, and complex sleep behaviors like sleepwalking or engaging in activities while not fully awake.

One of the primary concerns with Suvorexant is its potential to cause next-day drowsiness or impaired alertness, particularly if taken at higher doses. This is why it is crucial for patients to ensure they have a full seven hours available for sleep before taking the medication.

Suvorexant is contraindicated in individuals with narcolepsy, as the drug's mechanism of action directly interferes with orexin signaling, which is already compromised in those with this condition. Additionally, caution is advised for individuals with severe liver impairment, as they may have reduced clearance of the medication from their system.

Another significant consideration is the risk of central nervous system depression. Patients should avoid consuming alcohol or other CNS depressants alongside Suvorexant, as these can enhance the sedative effects of the drug and increase the risk of adverse outcomes.

What Other Drugs Will Affect Suvorexant

The efficacy and safety of Suvorexant can be influenced by the concurrent use of other medications. Suvorexant is metabolized primarily by the cytochrome P450 3A (CYP3A) enzyme, meaning drugs that strongly inhibit or induce this enzyme can significantly alter the pharmacokinetics of Suvorexant.

CYP3A inhibitors, such as certain antifungal agents (e.g., ketoconazole), antibiotics (e.g., clarithromycin), and protease inhibitors used in HIV treatment (e.g., ritonavir), can increase the plasma concentration of Suvorexant, heightening the risk of side effects. In such cases, a lower dose of Suvorexant may be necessary to avoid adverse effects.

Conversely, CYP3A inducers, including drugs like rifampin (an antibiotic) and certain anticonvulsants (e.g., carbamazepine), can decrease the plasma concentration of Suvorexant, potentially reducing its efficacy. Patients taking these medications may require a higher dose of Suvorexant, but this should only be done under medical supervision to ensure safety.

Other drugs that may interact with Suvorexant include those with sedative properties, such as benzodiazepines, opioid analgesics, and some antidepressants. Combining these with Suvorexant can amplify CNS depressant effects, raising the risk of excessive sedation, respiratory depression, and other severe adverse effects.

In summary, while Suvorexant offers a novel approach to treating insomnia by targeting the orexin system, it is essential to consider the potential interactions with other medications and substances. Always consult with a healthcare provider before starting or adjusting the dose of Suvorexant to ensure it is used safely and effectively.