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Back to Benzodiazipines

Name: Lorazepam

Pregnancy Category D
C-IV controlled substance

Drug classes

  • Benzodiazepine
  • Antianxiety drug
  • Sedative/hypnotic

Therapeutic actions

Exact mechanisms of action are not understood; acts mainly at subcortical levels of the CNS, leaving the cortex relatively unaffected. Main sites of action may be the limbic system and reticular formation; benzodiazepines potentiate the effects of GABA, an inhibitory neurotransmitter; anxiolytic effects occur at doses well below those  necessary to cause sedation and ataxia.


Management of anxiety disorders or for short-term relief of symptoms of anxiety or anxiety associated with depression (oral)

Preanesthetic medication in adults to produce sedation, relieve anxiety, and decrease recall of events related to surgery (parenteral)

Unlabeled parenteral use-management of status epilepticus, chemotherapy induced nausea and vomiting, acute alcohol withdrawal


Contraindicated in the presence of hypersensitivity to benzodiazepines, propylene glycol, polyethylene glycol or benzyl alcohol (parenteral lorazepam); psychoses; acute narrow-angle glaucoma; shock; coma; acute alcoholic intoxication with depression of vital signs; pregnancy (crosses the placenta; risk of congenital malformations and neonatal withdrawal syndrome); labor and delivery ("floppy infant" syndrome reported when mothers were given benzodiazepines during labor); and lactation.

Use caution in the presence of impaired liver or kidney function or debilitation.

Adverse effects

  • CNS: Transient, mild drowsiness initially; sedation, depression, lethargy, apathy, fatigue, lightheadedness, disorientation, anger, hostility, episodes of mania and hypomania, restlessness, confusion, crying, delirium, headache, slurred speech, dysarthria, stupor, rigidity, tremor, dystonia, vertigo, euphoria, nervousness, difficulty concentrating, vivid dreams, psychomotor retardation, extrapyramidal symptoms; mild paradoxical excitatory reactions during first 2 wk of
  • GI: Constipation, diarrhea, dry mouth, salivation, nausea, anorexia, vomiting, difficulty in swallowing, gastric disorders, hepatic dysfunction
  • CV: Bradycardia, tachycardia, cardiovascular collapse, hypertension and hypotension, palpitations, edema
  • Hematologic: Elevations of blood enzymes: LDH, alkaline phosphatase, SGOT, SGPT; blood dyscrasias: agranulocytosis, leukopenia
  • GU: Incontinence, urinary retention, changes in libido, menstrual irregularities
  • EENT: Visual and auditory disturbances, diplopia, nystagmus, depressed hearing, nasal congestion
  • Dermatologic: Urticaria, pruritus, skin rash, dermatitis
  • Other: Hiccups, fever, diaphoresis, paresthesias, muscular disturbances, gynecomastia. Drug dependence with withdrawal syndrome when drug is discontinued; more common with abrupt discontinuation of higher dosage used for longer than 4 mo.

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