Diazepam !

A long-acting benzodiazepine for anxiety, alcohol withdrawal, muscle spasm and seizures. It and its active metabolites stay in the body for days.

Updated 2026-11-01

Class: Benzodiazepines
Receptor: GABA-A receptor, benzodiazepine site
ATC code: N05BA01
WHO Model List of Essential Medicines

GABA-A receptor, benzodiazepine siteDiazepam

The figure shows diazepam itself bound to the human GABA-A receptor (α1β2γ2) together with GABA.

Target in 3D: GABA-A receptor, benzodiazepine site. PDB structure 6X3X (RCSB PDB, public domain). View the structure at RCSB PDB

Mechanism of action

Diazepam binds the benzodiazepine site of the GABA-A receptor and makes GABA open the chloride channel more often. The extra inhibition gives anxiolytic, sedative, muscle-relaxant, anticonvulsant and amnestic effects. The liver turns it into active metabolites (desmethyldiazepam, temazepam and oxazepam), so its effect lasts long.

Binds the benzodiazepine site of the GABA-A receptor
GABA opens the chloride channel more often
Chloride enters and the neuron is inhibited
Anxiety, muscle spasm and seizures are calmed

Pharmacokinetics

Absorption: More than 90% absorbed by mouth; peak in about 1 to 1.5 hours; food slows absorption
Metabolism: In the liver by CYP3A4 and CYP2C19 to active desmethyldiazepam and temazepam, then oxazepam
Half-life: Up to 48 hours for diazepam and up to 100 hours for desmethyldiazepam
Onset and duration: Fast after intravenous injection

Indications

Anxiety disorders and short-term relief of anxiety Generalized anxiety disorder →
Acute alcohol withdrawal (agitation, tremor, delirium tremens) Alcohol withdrawal and delirium tremens →
Status epilepticus, as add-on treatment (injection) Status epilepticus →
Muscle spasm, spasticity and tetanus, as add-on treatment Tetanus →
Sedation before endoscopy, cardioversion or surgery (injection)

Adverse effects

Common

Drowsiness and tiredness
Unsteadiness (ataxia) and muscle weakness
Confusion and memory problems, especially in older adults
Pain and phlebitis at the injection site

Contraindications

Hypersensitivity to diazepam
Acute narrow-angle glaucoma
Myasthenia gravis, severe respiratory insufficiency, sleep apnoea (oral form)
Severe liver failure (oral form)
Infants under 6 months (oral form)

Key interactions

Opioids: Profound sedation, respiratory depression, coma and death
Alcohol and other central nervous system depressants: Additive sedation and breathing depression
CYP3A4 and CYP2C19 inhibitors (cimetidine, ketoconazole, fluvoxamine, fluoxetine, omeprazole): Longer and stronger sedation
Phenytoin: Phenytoin clearance may fall

What is monitored

Breathing, oxygen saturation and level of consciousness, above all after IV doses
Blood pressure during IV use
Accumulation and falls in older adults
Signs of misuse or dependence with long use

Administration and safety

IV: injected slowly into a large vein, never into the small veins of the hand or wrist
Not mixed or diluted with other solutions or drugs in the syringe or bag
Intra-arterial injection and extravasation are avoided
Airway and ventilation equipment ready before IV use
Contains benzyl alcohol: risk of gasping syndrome in premature infants

Nursing care

Before each dose, check level of alertness, breathing rate and oxygen saturation
Ask about opioids, alcohol and other sedatives
Prevent falls, especially in older adults (unsteadiness, confusion)
Teach not to drive or drink alcohol and not to stop the medicine suddenly
Check the IV site for redness, pain or swelling

Pregnancy and breastfeeding

Use late in pregnancy can cause sedation and withdrawal symptoms in the newborn, who is watched after birth.

Test yourself

Think of the answer, then tap the question to see it.

Why does diazepam act for so long with regular use?

Its active metabolite desmethyldiazepam has a half-life of up to about 100 hours.

Into which veins is IV diazepam not injected, and why?

Small veins of the hand or wrist, because of thrombosis, phlebitis and irritation.

What are three emergency uses of diazepam?

Status epilepticus, alcohol withdrawal and tetanus spasms.

Add to my cards (3)

← Back to the class: Benzodiazepines

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: DailyMed - DIAZEPAM tablet (DailyMed (U.S. National Library of Medicine), 2026); DailyMed - DIAZEPAM injection, solution (DailyMed (U.S. National Library of Medicine), 2026); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); 6X3X: Human GABAA receptor alpha1-beta2-gamma2 subtype in complex with GABA plus diazepam (RCSB Protein Data Bank, 2020).

Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake

Representative model, for educational purposes only.