Lemborexant is a newer orexin receptor antagonist which is submitted to US FDA for review as new drug application for the treatment of insomnia after completing two key Phase 3 studies of lemborexant – SUNRISE 1 (Study 304) and SUNRISE 2 (Study 303).
Lemborexant is a white to off-white powder that is practically insoluble in water.
Lemborexant is a novel orexin receptor antagonist and is used in the treatment of insomnia, characterised by difficulties with sleep onset or sleep maintenance. Orexins are neuropeptides involved in regulating sleep and arousal by promoting wakefulness. Lemborexant blocks the binding of orexins A and B to their receptors 1 and 2 thereby reducing wakefulness and promoting sleep. Suvorexant is the other orexin receptor antagonist marketed in Australia for insomnia.
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Effect of food
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High-fat & high-calorie meal delay Tmax & reduce Cmax
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Tmax
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1 to 3 hours
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Half-life
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17 hours (5 mg) and 19 hours (10 mg)
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Metabolism
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primarily metabolized by CYP3A4
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Excretion
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Urine (29%); feces (57%)
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Synthesis route of Lemborexant
Lemborexant is metabolized by CYP3A4 and is susceptible to interactions with medications such as amiodarone, amlodipine, carbamazepine, clarithromycin, diltiazem, fluoxetine and phenytoin. Lemborexant may affect other medications metabolised by CYP2B6, such as bupropion and methadone. Alcohol should be avoided: a single dose of alcohol can increase lemborexant concentrations up to 70%.
The mechanism of action of lemborexant in the treatment of insomnia is Blocks the binding of wake-promoting neuropeptides orexin A and orexin B to receptors OX1R and OX2R, presumed to suppress wake drive.
