Ramelteon

Q: Melatonin is a chronobiotic?

A) True

B) false

Answer: A

Melatonin receptor agonists such as Ramelteon are increasingly used in ICUs. Ramelteon binds to the melatonin 1 and 2 receptors (MT1, MT2). It inhibits the wakefulness-promoting activity of the suprachiasmatic nucleus. It is most effective when patients have difficulty falling asleep. It reduces the time dedicated to light sleep but its efficacy on sleep continuity is not remarkable. Also, it has shown no improvement in daytime function.

Any hormone/chemical which helps to regulate circadian rhythm is called a chronobiotic.

#sleep

References:

1. Emens JS, Burgess HJ. Effect of Light and Melatonin and Other Melatonin Receptor Agonists on Human Circadian Physiology. Sleep Med Clin 2015; 10:435.

2. Dawson D, Armstrong SM. Chronobiotics--drugs that shift rhythms. Pharmacol Ther. 1996;69(1):15-36. doi: 10.1016/0163-7258(95)02020-9. PMID: 8857301.