Lorazepam
An intermediate-acting benzodiazepine used for anxiety, for status epilepticus and to sedate before surgery.
Drug card
- Class
- Benzodiazepine
- How it works
- Boosting GABA at GABA-A receptors, so chloride channels open more often
- Used for
- Anxiety disorders, short term
- Status epilepticus
- Sedation and amnesia before surgery
- Insomnia caused by anxiety
- Known for
- Sedation and drowsiness
- Slowed breathing, especially with opioids
- Its name
- -azepam, -azolam means a benzodiazepine
Study it as a flashcard, and it comes back before you forget it.
Mechanism of action
How does lorazepam work?
Lorazepam binds the benzodiazepine site on the GABA-A receptor and raises the receptor's affinity for GABA without displacing it, so chloride channels open more often. The liver conjugates it to an inactive glucuronide, and it has no active metabolites; its half-life is about 12 hours.
Like other 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.
Uses
What is lorazepam used for?
- Anxiety disorders, short term
- Status epilepticus
- Sedation and amnesia before surgery
- Insomnia caused by anxiety
Side effects
Side effects of lorazepam
- Sedation and drowsinessKnown for
- Slowed breathing, especially with opioidsKnown forSerious
- Dizziness
- Unsteadiness (ataxia)
- Memory problems (amnesia)
- Confusion and disorientation
- Low blood pressure
- Dependence and misuseSerious
- Withdrawal reactions, such as seizures, if stopped suddenlySerious
- Hallucinations, low mood or disinhibition
- Blood disorders, such as low platelets or white cellsSerious
- Falls, mainly in older peopleSerious
Known for marks what an exam expects you to know it for.
Watch for
Cautions and what sets it apart
- Injection: keep airway and breathing support ready, as hypoventilation and apnea can occur, more so in older or very ill people.
- Contraindicated in acute narrow-angle glaucoma, sleep apnea and severe respiratory insufficiency.
- Never inject into an artery: arteriospasm can lead to gangrene.
- Taper gradually after regular use to avoid withdrawal reactions.
Good to know: Used by mouth for anxiety and by injection for status epilepticus and premedication, where its amnesic effect reduces memory of the procedure.
Remember it
A way to remember it
CALMS
- C
- Convulsions controlled
- A
- Anxiety relief
- L
- Loss of memory for events after a dose (amnesia)
- M
- Muscle relaxation
- S
- Sedation
Written for biofideX
Its name
-azepam, -azolam means benzodiazepine
Diazepam and lorazepam end in -azepam; alprazolam and midazolam, with an added triazole or imidazole ring, end in -azolam. Clobazam and chlordiazepoxide are benzodiazepines too.
- Every drug name stem
Its class
Benzodiazepines
Other benzodiazepines with a card:
Easily mixed up with Z-drugs.
Sources
Checked against
Written for biofideX in plain words, after checking these references:
- Lorazepam injection: label (DailyMed)
- Lorazepam tablets: label (DailyMed)
- Lorazepam (NCI Thesaurus)
- Lorazepam (NHS)
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.
Depression, anxiety and sleep
Lorazepam is one of 15 drugs practiced together here: their classes, how they work, what they treat and what they're known for.
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