Lorazepam

Brand name

  • Ativan®

Drug Class

  1. Anxiolytic agent
  2. Sedative
  3. Anticonvulsant

Preparations

  • Tablets: 0.5 mg, 1 mg, and 2 mg
  • Tablets sublingual: 0.5 mg, 1 mg, 2 mg

Indications

  1. Management of alcohol withdrawal management
  2. Management of delirium tremens
  3. Muscle relaxant
  4. Management of anxiety disorders or for the short-term relief of the symptoms of anxiety or anxiety associated with depressive symptoms.
  5. Anxiety or tension associated with the stress of everyday life usually does not require treatment with an anxiolytic.
  6. The effectiveness of Ativan (lorazepam) in long-term use, that is, more than 4 months, has not been assessed by systematic clinical studies.

Metabolism

  1. Half life: 10-70 hrs

Dosing

The usual range is 2 to 6 mg/day given in divided doses

Anticonvulsant:

  • 05 mg/kg IV (up to 7 mg) which can be repeated in 5 min
    1. Anxiety:
  • 2 to 3 mg/day given bid. or tid.

Insomnia:

  • a single daily dose of 2 to 4 mg may be given, usually at bedtime.

For elderly or debilitated patients:

  • Initial dosage of 1 to 2 mg/day in divided doses is recommended, to be adjusted as needed and tolerated.

The dosage of Ativan (lorazepam) should be increased gradually when needed to help avoid adverse effects.

  1. When higher dosage is indicated, the evening dose should be increased before the daytime doses.

Drug Interactions

Causes sedation if used with CNS depressants such as:

  • Alcohol
  • Barbiturates
  • Antipsychotics
  • sedative/hypnotics
  • anxiolytics
  • antidepressants
  • narcotic analgesics
  • sedative antihistamines
  • Anticonvulsants
  • Anesthetics

Concomitant use of clozapine and lorazepam may produce:

  • marked sedation
  • excessive salivation
  • hypotension
  • ataxia
  • delirium
  • respiratory arrest

Concurrent administration of lorazepam with valproate results in:

  • increased plasma concentrations and reduced clearance of lorazepam.
  • Lorazepam dosage should be reduced to approximately 50% when coadministered with valproate.

Concurrent administration of lorazepam with probenecid may result in:

  • a more rapid onset or prolonged effect of lorazepam due to increased half-life and decreased total clearance.
  • Lorazepam dosage needs to be reduced by approximately 50% when coadministered with probenecid.
  • The effects of probenecid and valproate on lorazepam may be due to inhibition of glucuronidation.

Administration of theophylline or aminophylline:

  • may reduce the sedative effects of benzodiazepines, including lorazepam.

Adverse Effects

General:

  • Fatigue
  • Diplopia
  • Blurred vision
  • Hypersensitivity reactions,
  • Anaphylactic reactions

Respiratory:

  • Respiratory depression and partial airway obstruction, especially when combined with narcotics
  • Respiratory depression
  • Apnea
  • Worsening of sleep apnea

Cardiovascular:

  • Hypotension

CNS:

  • paradoxical reactions (irritability, excitability);
  • may make depression or psychosis worse
  • amnesia
  • sedation
  • dizziness
  • weakness
  • unsteadiness
  • drowsiness
  • confusion
  • disorientation
  • depression
  • unmasking of depression
  • disinhibition
  • euphoria
  • suicidal ideation/attempt
  • ataxia
  • asthenia
  • extrapyramidal symptoms
  • convulsions/seizures tremor
  • vertigo
  • dysarthria/slurred speech
  • headache
  • coma

GI:

  • nausea,
  • change in appetite,
  • constipation,
  • jaundice,
  • increase in bilirubin,
  • increase in liver transaminases,
  • increase in alkaline phosphatase

Urogenital:

  • change in libido
  • impotence
  • decreased orgasm

Skin:

  • dermatological symptoms
  • allergic skin reactions
  • alopecia

Endocrine:

  • SIADH,
  • hyponatremia

Blood:

  • Thrombocytopenia
  • agranulocytosis
  • pancytopenia

Pregnancy and Breastfeeding

  1. Avoid using during nursing

Warning

Sign and symptoms of toxicity:

  • central nervous system depression ranging from drowsiness to
  • coma
  • dysarthria
  • lethargy
  • ataxia
  • hypotonia
  • hypotension
  • cardiovascular depression
  • respiratory depression,
  • hypnotic state
  • coma

Management:

  • When there is a risk of aspiration, induction of emesis is not recommended.
  • Gastric lavage may be indicated if performed soon after ingestion or in symptomatic patients.
  • Administration of activated charcoal may also limit drug absorption.
  • Hypotension, though unlikely, usually may be controlled with norepinephrine bitartrate injection.
  • Lorazepam is poorly dialyzable. Lorazepam glucuronide, the inactive metabolite, may be highly dialyzable
  • Flumazeil

Section

This document is prepared by the “Mental Health for All” team. This document is provided for information purposes only and does not necessarily represent endorsement by or an official position of the Essentials of Medicine. Advice on the treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient or is familiar with that patient’s medical history.

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