Efficacy of the Administration of Melatonin 5mg in the Prevention of Delirium in Older Adults Hospitalized in the Emergency Department

Melatonia is useful for the treatment of sleep disorders due to the interruption of the circadian rhythm, secondary to alterations caused by the environment. The doses of 5 to 10mg oral or sublingual can improve the quality of the sleep-wake cycle and alertness in short-term use. Mechanism of action of melatonin are: 1. Binding to membrane receptors: MT1 and MT2 coupled to G protein 2. \- Union to nuclear receptors. 3. \- Interaction with cytosolic proteins. 4. \- Antioxidant of direct and indirect action. 5. \- Interaction with mitochondria. Melatonin circulates 80% bound to albumin and the rest in free form in plasma, 85-90% is metabolized by 6-hydroxymelatonin in the liver, which is then conjugated with sulfuric acid (70-80%) or glucuronic ( 5-3%), and is excreted in urine and feces. Melatonin and its metabolites act as catalytic antioxidants to safeguard mitochondrial electron transfer reactions, therefore, increases the efficiency of energy metabolism. Melatonin synthesis decreases significantly as age progresses and changes in the circadian cycle have been associated with accelerated aging.