sedative

A sedative-hypnotic drug is a substance used to reduce tension and anxiety, inducing calmness (sedation) or sleep (hypnosis). These drugs primarily depress the central nervous system. While other drugs can also cause calming effects, sedative-hypnotics are distinct in their ability to do so without significantly altering mood or pain sensitivity.1

Historically, alcohol and opium were the main sedative-hypnotics. The 19th century saw the introduction of bromide salts, chloral hydrate, and paraldehyde. The 20th century brought barbiturates, such as phenobarbital, which were widely used as sleeping pills but carried risks of tolerance and addiction.1

In the mid-20th century, benzodiazepines (minor tranquilizers) emerged as a safer alternative, being more effective for anxiety and less prone to addiction and severe central nervous system depression than barbiturates. While other drugs like antipsychotics, antidepressants, and antihistamines can cause drowsiness, it's not their primary function.1