Benzodiazepines are a class of psychoactive drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. The first such drug, chlordiazepoxide, was discovered accidentally by Leo Sternbach in 1955, and made available in 1960 by Hoffmann–La Roche, which, since 1963, has also marketed the benzodiazepine diazepam.
Benzodiazepines enhance the effect of the neurotransmitter gamma-aminobutyric acid (GABA) at the GABAA receptor, resulting in sedative, hypnotic (sleep-inducing), anxiolytic (anti-anxiety), anticonvulsant, and muscle relaxant properties. High doses of many shorter-acting benzodiazepines may also cause anterograde amnesia and dissociation.
These properties make benzodiazepines useful in treating anxiety, insomnia, agitation, seizures, muscle spasms, alcohol withdrawal, and as a premedication for medical or dental procedures.
Benzodiazepines are categorized as either
short-,
intermediate-, or
long-acting;
short- and
intermediate-acting benzodiazepines are preferred for the treatment of insomnia;
longer-acting benzodiazepines are recommended for the treatment of anxiety.
Benzodiazepines are generally viewed as safe and effective for short-term use, although cognitive impairment and paradoxical effects, such as aggression or behavioral disinhibition, occasionally occur. Long-term use is controversial because of concerns about adverse psychological and physical effects, decreasing effectiveness, and physical dependence and withdrawal.
The benzodiazepines are essential drugs in palliative care.
Uses include the treatment of:
- insomnia
- anxiety and panic disorder
- acute psychotic agitation
- terminal agitation/restlessness
- skeletal muscle spasm
- seizures
- myoclonus
- nausea and vomiting
- alcohol withdrawal
- intractable pruritus
- premedication for painful procedure
Commonly used benzodiazepines
- diazepam (PO, IV)
- midazolam (PO, SC, CSCI)
- clonazepam (PO, SL, SC, IV)
- lorazepam (SL, PO, IV)
- oxazepam (PO)
- temazepam (PO)
Side effects include
- dose-dependent drowsiness
- impaired psychomotor skills (e.g., impaired driving ability)
- daytime fatigue
- cognitive impairment
- hypotonia (unsteadiness/ataxia)
Adapted from Wikipedia, the free encyclopedia. Internet. Accessed on October 5, 2016.