Benzodiazepines and Z-drugs · Psychiatry
Lorazepam
Ativan®(brand names vary by market)
The benzodiazepine the liver does not have to think about.
Also: injection, oral liquid
Mechanism
Positive allosteric modulation at GABA-A, increasing chloride channel opening frequency in response to the body's own GABA.
Indications
- Status epilepticus and acute seizures
- Alcohol withdrawal
- Severe acute anxiety, short term
- Procedural sedation
- Palliative agitation and breathlessness
Formulations
Dosing concepts
Liver disease
Cleared by glucuronidation rather than oxidation, so it is the benzodiazepine of choice in hepatic impairment and in older adults, where oxidative capacity falls.
Duration
Prescribed with a stop date. Dependence develops in weeks and the taper afterwards takes months.
Alcohol withdrawal
Symptom-triggered dosing against a validated scale outperforms fixed schedules and uses less drug overall.
Concepts, not prescribing instructions. Practice numbers live in current references and local protocols.
Pharmacokinetics
- Bioavailability
- ~90%
- Half-life
- 10 to 20 h
- Elimination
- hepatic: Glucuronidation only, with no active metabolites: the reason it is safe when the liver is not
- Protein binding
- ~85%
Adverse effects
- Sedationcommon
- Falls and fractures in older adultscommon & serious
- Anterograde amnesiacommon
- Respiratory depressionseriousChiefly in combination with opioids or alcohol; alone it is comparatively forgiving.
- Tolerance and dependencecommon & serious
- Paradoxical agitationseriousEspecially in children and older adults.
Contraindications & precautions
Contraindications
- Severe respiratory failure
- Myasthenia gravis
- Severe sleep apnoea
Precautions
- Concurrent opioids
- Older adults
- History of substance use disorder
- Long-term use
Interactions
No curated interaction entries yet for this agent.
Monitoring
Sedation and respiratory rate, particularly with opioids
The combination is where the deaths are
Duration of therapy
The single most predictive safety variable
Falls and cognition in older adults
The realistic harm outside hospital
Counselling points
- This is a short-term medicine; we will agree when it stops.
- Do not drink alcohol with it.
- Do not drive until you know how it affects you.
- Do not stop it abruptly if you have taken it for weeks: it needs to be reduced slowly.
Clinical pearls
- Benzodiazepine plus opioid is the combination behind a large share of prescription overdose deaths, and it is co-prescribed constantly. Every instance deserves a stated reason.
- In alcohol withdrawal a benzodiazepine is the treatment and an antipsychotic is not; giving haloperidol instead lowers the seizure threshold in exactly the patient who cannot afford it.
References & review
- Lorazepam product monograph (consult the current version for your market) (monograph)
- Goodman & Gilman's The Pharmacological Basis of Therapeutics, 14th ed. (reference-work)
Last reviewed 2026-08-16 · jurisdiction: global · drug information changes; verify against current references before practice use.