Sedativa

Sedatives are substances that depress the central nervous system to produce calmness, relieve anxiety, or induce sleep. They are used for anxiety and insomnia, to sedate patients during procedures, and as part of anesthesia.

Most sedatives work by enhancing GABA, the brain's primary inhibitory neurotransmitter, at GABA-A receptors, increasing neuronal inhibition. Onset and duration vary; some agents act quickly and for a short time, others have longer effects.

Common categories include benzodiazepines (diazepam, lorazepam, temazepam), non-benzodiazepine hypnotics known as Z-drugs (zolpidem, zaleplon, eszopiclone), and barbiturates (phenobarbital). Over-the-counter sedatives such as diphenhydramine are also used for short-term sleep.

Other medications with sedating properties include certain antidepressants (mirtazapine, trazodone) and some antipsychotics, used for insomnia or agitation in specific conditions. In clinical settings, sedatives used for anesthesia include propofol and etomidate.

Indications include anxiety relief, insomnia management, procedural or pre-anesthesia sedation, seizure control in some cases, and agitation reduction in various conditions.

Risks include daytime drowsiness, impaired coordination, confusion, and, at high doses or with other depressants, respiratory depression. Long-term use can cause tolerance, dependence, and withdrawal. Caution is advised in the elderly, those with sleep apnea or lung disease, and during pregnancy. Sedatives should be used at the lowest effective dose and typically for short durations when possible.