Benzodiazepines

Benzodiazepines bind their own site on the GABA-A receptor, apart from the GABA site, and increase the receptor's affinity for GABA. The chloride channel then opens more often, hyperpolarizing neurons and damping their firing. Depending on the drug and dose, the result is anxiety relief, sedation, muscle relaxation, seizure control and amnesia.

• DiazepamLonger-acting than lorazepam, alprazolam or midazolam: its active metabolite desmethyldiazepam lasts for days, so effects accumulate with regular use.
• LorazepamUsed by mouth for anxiety and by injection for status epilepticus and premedication, where its amnesic effect reduces memory of the procedure.
• AlprazolamThe only benzodiazepine here licensed for panic disorder; because CYP3A4 clears it, many interacting drugs change its levels.
• MidazolamThe shortest-acting benzodiazepine here; besides IV and IM use, an oromucosal (buccal) form is given to children with epilepsy for prolonged seizures.

• Anxiety disorders and short-term anxiety relief
• Panic disorder
• Insomnia, short term
• Status epilepticus and other seizure emergencies
• Alcohol withdrawal
• Sedation before surgery or procedures

• Drowsiness and sedationKnown for
• Dependence, misuse and addictionKnown forSerious
• Slowed breathing, dangerous with opioidsKnown forSerious
• Unsteadiness and poor coordination (ataxia)
• Withdrawal reactions, even seizures, if stopped suddenlySerious
• Memory loss for events after a dose (amnesia)
• Confusion, especially in older people
• Falls and fractures in older peopleSerious
• Paradoxical agitation or aggression
• Low blood pressure

What the class has in common. Each drug's card has its own, and Known for marks what an exam expects you to know.

• Taken with opioids, alcohol or other CNS depressants, they can deepen sedation and slow breathing enough to cause coma or death.
• Use the lowest dose for the shortest time, and taper gradually after regular use to avoid withdrawal reactions.
• Avoid in severe respiratory insufficiency, sleep apnea, myasthenia gravis and acute narrow-angle glaucoma.
• Flumazenil reverses their effects and should be at hand when they are given intravenously.

Written for biofideX in plain words, after checking these references:

• FDA requiring Boxed Warning updated to improve safe use of benzodiazepine drug class (FDA)
• Benzodiazepine (NCI Thesaurus)
• Diazepam tablets: label (DailyMed)
• Lorazepam injection: label (DailyMed)

For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.