sedativi

Sedativi, or sedatives, are a class of psychoactive drugs that depress central nervous system activity to produce calmness, reduce agitation and anxiety, and at higher doses promote sleep or sedation. They are distinct from anesthetics and from hypnotics; some agents are used primarily for anxiety (anxiolytics), others as sleep aids (hypnotics), and some for procedural or perioperative sedation.

Most sedatives act by enhancing GABAergic inhibition, typically as positive allosteric modulators of the GABA-A receptor, increasing chloride ion influx and dampening neuronal firing. This produces sedative, anxiolytic, anticonvulsant, and muscle-relaxant effects. Other drugs such as dexmedetomidine induce sedation via different pathways (alpha-2 adrenergic agonism) and tend to preserve respiration more than classic CNS depressants.

Common sedatives include benzodiazepines (diazepam, lorazepam, midazolam) used for anxiety, premedication, and procedural sedation; non-benzodiazepine Z-drugs (zolpidem, zaleplon, eszopiclone) primarily for insomnia; barbiturates (phenobarbital) were once common but are now limited due to risk of tolerance and withdrawal; chloral hydrate is rarely used; dexmedetomidine used in critical care and anesthesia. Dosing, duration of effect, and cautions vary by agent.

Use carries risks of dependence, tolerance, and withdrawal; concomitant use with alcohol or opioids can cause dangerous respiratory depression; cognitive impairment, confusion and falls are concerns, especially in older adults. Potential interactions with other CNS depressants and impact on sleep architecture. Many sedatives are regulated substances and require medical prescription in many jurisdictions.

In clinical practice, guidelines emphasize the lowest effective dose for the shortest duration, careful monitoring, and gradual tapering to minimize withdrawal. Non-pharmacological approaches are preferred for chronic insomnia or anxiety when possible.