Chapter 13: Central Nervous System Depressants and Muscle Relaxants

Sedatives

Drugs that reduce nervousness, excitability, and irritability without causing sleep, but can become hypnotics in large doses.

Hypnotics

Drugs that cause sleep and have a more potent effect on the central nervous system (CNS) than sedatives.

Sedative-Hypnotics

Drugs that can act as both sedatives and hypnotics depending on dose and patient responsiveness, classified into barbiturates, benzodiazepines, and miscellaneous drugs.

Rapid Eye Movement (REM) Sleep

A stage of sleep characterized by rapid eye movements, vivid dreams, and reduced muscle activity.

Non-REM Sleep

A stage of sleep that does not include rapid eye movements and is characterized by deep sleep and restfulness.

REM Interference

Reduction in the cumulative amount of REM sleep due to prolonged sedative-hypnotic use, leading to daytime fatigue.

REM Rebound

Abnormally large amount of REM sleep after discontinuing a sedative-hypnotic drug, often resulting in frequent and vivid dreams.

Benzodiazepines

Drugs commonly used for sedation, anxiety relief, sleep induction, and treatment of acute seizure disorders, with a relatively favorable adverse effect profile.

Barbiturates

CNS depressants that act on the brainstem, used for sedation, anesthesia, and anticonvulsant purposes, with a low therapeutic index and potential for adverse effects.

Muscle Relaxants

Drugs acting within the CNS to relieve pain associated with skeletal muscle spasms, often used in conjunction with rest and physical therapy.