Lorazepam
Class
High-potency short-to-intermediate-acting 3-hydroxy benzodiazepine
Indications
Short-term management of severe anxiety
Short-term treatment of insomnia
Convulsive status epilepticus
Treatment and prevention of alcohol withdrawal syndrome
Sedation induction and anterograde amnesia
Impaired liver function is not a hazard with lorazepam
Does not require oxidation, hepatic or otherwise, for its metabolism
Administration/Absorption
IV
Oral
Dosage
Distribution
Readily absorbed with an absolute bioavailability of 90%
85% protein bound
Mechanism
Binds to an allosteric site on GABA-A receptors, which are pentameric ionotropic receptors in the CNS
Binding potentiates the effects of the inhibitory neurotransmitter GABA
Opens the chloride channel in the receptor, allowing chloride influx and causing hyperpolerization of the neuron
Excretion
Lorazepam is rapidly conjugated at its 3-hydroxy group into lorazepam glucuronide which is then excreted in the urine
Half-life 12 hours
Side effects
Any of the five intrinsic benzodiazepine effects possessed by benzodiazepines
Sedative/hypnotic, muscle relaxant, anxiolytic, amnesic, and anticonvulsant
Paradoxical effects
Suicidality
Withdrawal effects
Interactions
Contraindications