Melatonin prolonged release (Circadin®) has been launched for the treatment of primary insomnia.
It is currently only recommended for patients aged 55 years or older and for a period of three weeks. The Regional Drugs and Therapeutics Centre has published a review that highlights the lack of comparative trials, small effect size and cost difference.
Similarly, the National Prescribing Centre has written a Rapid Review that draws attention to the need for clinicians to accurately diagnose primary insomnia and provide patient education to improve sleep hygiene. The lack of comparative data means it is difficult to place this therapy in relation to existing treatments, including hypnotics.
Action: The benefits of the drug are modest. Usage is currently limited to patients aged 55 years and over who already practice behaviours in keeping with good sleep hygiene.