Treatment of a patient with a circadian sleep-wake disorder using a combination of melatonin and metoprolol

Abstract

Circadian rhythm sleep-wake disorders result from the lack of synchronization between endogenous circadian rhythms and daily environmental or behavioral cycles. Current treatment of circadian rhythm sleep-wake disorders relies on strengthening normal zeitgebers, or temporal cues, through the combination of strict behavioral modification, controlled light exposure, and supplemental melatonin or melatonin receptor agonists. These therapies can be difficult to maintain and are supported with only limited clinical outcome data. The effectiveness of exogenous melatonin, in particular, may be reduced by the patient's continued production of endogenous melatonin withatemporalpattern that is not conduciveto the desired sleep schedule.Herewedescribe thecaseofasingle, sighted patient withacircadianrhythm sleepwake disorder who benefited from the combined use of a beta blocker to suppress endogenous melatonin secretion along with the timed administration of exogenous melatonin. We suggest that the positive results obtained justify further study of this mechanism-guided approach.