| The pharmacological effects of the benzodiazepines are a result of their interaction with the central nervous system, their effects being [[sedation]], [[hypnosis]], decreased [[anxiety]], [[muscle relaxation]], [[anterograde amnesia]] and anticonvulsant activity. At high doses, when given intravenously, the benzodiazepines may also cause coronary vasodilation and neuromuscular blockade. The CNS effects of benzodiazepines are believed to be mediated by activation of GABA A receptors and modulation of their inhibition of neurotransmission.
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| Benzodiazepines in current use, with their initial brand name and year of approval, include alprazolam (Xanax, 1981), chlordiazepoxide (Librium, 1960), clonazepam (Klonopin, 1997), clorazepate (Tranxene, 1972), diazepam (Valium, 1963), estazolam (ProSom, 1990), flurazepam (Dalmane, 1970), lorazepam (Ativan, 1977), midazolam (Versed, 1985), oxazepam (Serax, 1965), quazepam (Doral, 1985), temazepam (Restoril, 1981), triazolam (Halcion, 1982), and most recently clobazam (2011). They are variously indicated for treatment of [[anxiety]], [[alcohol withdrawal]] symptoms, [[insomnia]], [[muscle relaxation]], [[panic disorder]]s and seizure disorders. The benzodiazepines all share similar activity and clinical effects, but variability in dosing, pharmacokinetics, rapidity of uptake and half-life make them more suited for one or another of these indications. Thus, estazolam, flurazepam, quazepam, temazepam and triazolam are generally used as sleeping pills, whereas alprazolam, chlordiazepoxide, diazepam, and lorazepam are used largely in therapy of [[anxiety]]. Clobazam, clonazepam, and clorazepate are used as anticonvulsants, and high dose, parenteral diazepam and lorazepam are used for status epilepticus. Parenteral midazolam, diazepam and lorazepam are also used as anesthetics or anesthetic premedications.
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| Benzodiazepine therapy is uncommonly associated with serum enzyme elevations, and clinically apparent liver injury from the benzodiazepines is quite rare. Alprazolam, chlordiazepoxide, clonazepam, clorazepate, diazepam, flurazepam and triazolam have been linked to rare instances of cholestatic liver injury but the other benzodiazepines have not. The absence of reports of this rare adverse event, however, may be due to the fact that these other benzodiazepines are not as commonly or continuously used. Alternatively, the use of the sleeping aids in intermittent and low doses may favor their lack of hepatic injury.
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