Melatonin Use in the ICU: Mind the (Evidence) Gaps

The sleep cycle, an integral part of human health, consists of several stages with distinct characteristics and functions. It begins with a transition from wakefulness to sleep, known as the light sleep phase, followed by the restorative deep sleep phase, essential for physical recovery and growth. The cycle concludes with the Rapid Eye Movement (REM) phase, characterized by high brain activity and vivid dreaming. Insomnia, a prevalent sleep disorder, involves difficulty falling asleep, staying...

Sedatives and hypnotics encompass a wide range of substances, each with its unique mechanism of action, uses, and potential adverse effects.
Melatonin congeners like ramelteon (Rozerem) and tasimelteon (Hetlioz) selectively bind to melatonin receptors (MT1 and MT2) and thus mimic the actions of melatonin, a hormone that regulates sleep-wake cycles. Tasimelteon is primarily used for non-24-hour sleep-wake disorder, common in blind patients. They are also used to treat conditions like insomnia...

Substance use disorders involve a pattern of using drugs more extensively than intended and continuing use despite harmful consequences. This includes legal substances like alcohol and nicotine, as well as illegal drugs. These disorders often involve both physical and psychological dependence, reflecting compulsive use of substances that significantly alter thoughts, feelings, and behaviors, contributing to a major public health issue.
Understanding the concepts of physical dependence,...

Sedatives are drugs that alleviate anxiety, while hypnotics induce sleep. Both classes of medication suppress neuronal activity, leading to a calming effect for sedatives and facilitating sleep for hypnotics.
Sedative-hypnotics are categorized into barbiturates, benzodiazepines (BZDs), and non-benzodiazepines or Z-drugs. These drugs work by suppressing central nervous system activity, and this suppression is dose-dependent. Older sedative medications, like barbiturates, follow a linear curve in...

Restless Leg Syndrome (RLS), also known as Willis-Ekbom disease, is a neurological disorder characterized by an uncontrollable urge to move the legs due to uncomfortable sensations. These sensations typically occur during periods of rest or inactivity, particularly when lying down or sitting, and can severely disrupt sleep.
The exact cause of RLS is not fully understood, but it is believed to involve dopamine, a neurotransmitter that helps regulate muscle movement. Imbalances in dopamine levels...