Sedativo

Sedativo is a term used for substances that depress the central nervous system to produce calming, sedative, or hypnotic effects. They are employed to reduce anxiety, promote sleep, facilitate medical procedures, and provide anesthesia or intensive-care sedation. The category encompasses several drug classes with differing mechanisms, indications, and safety profiles.

Classification and mechanisms: Benzodiazepines (for example diazepam, lorazepam, temazepam) enhance the action of gamma-aminobutyric acid (GABA) at the GABA-A receptor, yielding anxiolysis, sedation, and amnesia. Non-benzodiazepine hypnotics (zolpidem, zaleplon, eszopiclone) act on the same receptor system but are chemically distinct. Barbiturates (phenobarbital) also potentiate GABA but carry higher risks of respiratory depression. Sedating antihistamines (diphenhydramine, doxylamine) induce drowsiness by blocking histamine H1 receptors. Other sedatives include agents like dexmedetomidine (an alpha-2 adrenergic agonist) used in intensive care, and certain antipsychotics or melatonin receptor agonists used for specific sleep disturbances.

Indications and considerations: Sedatives are used for anxiety relief, premedication for procedures, insomnia treatment, agitation control, and anesthesia management. Potential risks include drowsiness, cognitive impairment, impaired coordination, falls (especially in older adults), respiratory depression, hypotension, dependence, and withdrawal with prolonged use. Interactions with alcohol or other central nervous system depressants can increase danger. Safe use requires medical supervision, appropriate dosing, and consideration of comorbidities and concurrent medications.

See also: anxiolytics, hypnotics, anesthesia, sedation.