Insomnia is characterized subjectively and may consist of a variety of complaints, including difficulty falling asleep, difficulty maintaining sleep, or experiencing nonrestorative sleep. Despite a number of available treatments, insomnia is one of the most common medical complaints in general practice. It affects up to 30% of the adult population.
Suvorexant, an orexin receptor antagonist (ORA), is the first in a new class of drugs in development for the treatment of insomnia. The tablets promote transition from wake to sleep by inhibiting the wakefulness-promoting orexin neurons of the arousal system and aims to improve sleep onset and sleep maintenance. This unique alternative has a favourable tolerability and apparently limited side-effect profile.
The main mechanism of action of Suvorexant, is a potent dual orexin receptor antagonist that blocks both OX1R and OX2R, which promotes sleep through the binding inhibition of orexin A and B, neuropeptides that promote wakefulness. The advantage of this type of insomnia treatment is that the drug is generally well tolerated, has low potential for addiction or dependence and is not eliminated through the renal system.
As with other insomnia medications, Suvorexant has the potential to produce drowsiness the next day that might interfere with daily activities. This effect is observed with doses higher than 40 mg and increases proportionally with dosage increases.
Suvorexant has been approved by the USA FDA in August 2014 and is currently being marketed as Belsomra. The therapeutic goods administration (Australia’s regulatory body for medicines and medical devices) has tentatively approved Suvorexant for clinical use in cases of primary insomnia, but has limited intended use to 3 months (March 2015).
