USE OF MELATONIN FOR SLEEP AND CIRCADIAN-RHYTHM DISORDERS

Although not licensed as a drug, melatonin is widely sold as a nutriti onal supplement in the USA for its purported sleep-promoting and antia geing properties. In this article, we provide some guidelines for its use in sleep disorders medicine. In brief, melatonin appears to promot e sleep by producing corrective circadian phase shifts, thereby improv ing the alignment of the endogenous sleep propensity rhythm with the d esired sleep schedule. Melatonin may also have a direct soporific effe ct, especially when administered during the day. We suggest that the d irect soporific action results from the release of accumulated sleep d rive by melatonin's attenuation of the circadian alerting signal. Mela tonin has not been proven safe by the usual clinical trial criteria, b ut to date no catastrophes have been related to its use. Also, there i s little information about the safety and efficacy of chronic administ ration.