First Drug Approved for Non-24 DisorderAschenbrenner, Diane S., MS, RNAJN The American Journal of Nursing: June 2014 - Volume 114 - Issue 6 - p 20,21 doi: 10.1097/01.NAJ.0000450422.82136.30 Drug Watch Buy Abstract Author InformationAuthors Article MetricsMetrics Tasimelteon (Hetlioz) is the first drug approved for the treatment of non–24-hour sleep–wake (non-24) disorder in patients with total blindness. Non-24 disorder occurs when a person's 24-hour circadian rhythm isn't regulated in the brain because it can't receive the daylight that normally acts as a stimulus. Those afflicted will have a circadian rhythm longer than 24 hours, leading to a periodic extended inability to sleep at night. The most common adverse effects of tasimelteon are headache, elevated liver enzyme levels, nightmares or unusual dreams, disturbed sleep, upper respiratory or urinary tract infection, and drowsiness. Diane S. Aschenbrenner recently retired as course coordinator for undergraduate pharmacology at Johns Hopkins University School of Nursing in Baltimore, MD. She also coordinates Drug Watch: email@example.com. © 2014 Lippincott Williams & Wilkins. All rights reserved.