Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Benzodiazepine (long-acting) Pregnancy: Safety in human pregnancy not established; should not be used in the first and third trimesters. Possible small increase in risk of congenital malformation (particularly oral cleft) with first-trimester benzodiazepine use. High-dose or late-pregnancy/labour use can cause neonatal hypothermia, hypotonia ('Floppy Infant Syndrome'), respiratory depression and withdrawal. Contraindicated when planning pregnancy and in pregnancy unless compelling reasons. Benzodiazepines should not be given to breast-feeding mothers.

Diazepam

Brand names: Valium, Diazemuls (IV emulsion), Stesolid (rectal)

Diazepam is a long-acting benzodiazepine used for short-term relief of severe anxiety, alcohol withdrawal, status epilepticus, muscle spasm and as a sedative.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Anxiety states, obsessive-compulsive neuroses and other psychiatric disorders: 5-30 mg daily in divided doses
Route: Oral
Frequency: Daily in divided doses
Max: Up to 60 mg daily in divided doses for cerebral palsy, upper motor neurone spasticity and as an adjunct in epilepsy
As an anxiolytic, use the lowest dose that controls symptoms; should not be continued beyond 4 weeks and long-term chronic use is not recommended. Always taper off gradually. Other indications (SPC): alcohol withdrawal 5-20 mg repeated if necessary in 2-4 hours; insomnia associated with anxiety 5-15 mg before bedtime; cerebral palsy 5-60 mg daily in divided doses; upper motor neurone spasticity 5-60 mg daily in divided doses; muscle spasm / fibrositis / cervical spondylosis 5-15 mg daily in divided doses; adjunct in epilepsy 2-60 mg daily in divided doses; oral premedication before surgery 5-20 mg. Elderly and debilitated patients: doses should be half the above recommended doses. Hepatic impairment: may precipitate coma, so reduce dose or consider an alternative drug (severe hepatic insufficiency is a contraindication). Severe renal impairment: reduce the dose.

Dose adjustments

Renal

In severe renal impairment the dose should be reduced.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance, other benzodiazepines or any excipient
  • Phobic or obsessional states; chronic psychosis; hyperkinesis (paradoxical reactions may occur)
  • Acute pulmonary insufficiency; respiratory depression; acute or chronic severe respiratory insufficiency
  • Myasthenia gravis; sleep apnoea
  • Severe hepatic insufficiency; acute porphyria
  • Depression or anxiety with depression as monotherapy (suicide may be precipitated)
  • Planning a pregnancy; pregnancy (unless compelling reasons)

Side effects

  • Drowsiness (very common); ataxia, impaired motor ability, tremor, confusion
  • Anterograde amnesia (risk increases at higher doses)
  • Muscle weakness, fatigue, headache, dizziness, slurred speech
  • Increased salivary and bronchial secretion (particularly in children); respiratory depression
  • Dependence and withdrawal / rebound phenomena on chronic use; increased risk of falls and fractures in the elderly

Interactions

  • Opioids (increased risk of respiratory depression, sedation; limit dose and duration)
  • Other centrally acting agents (phenothiazines, antipsychotics, anxiolytics/sedatives, hypnotics, anticonvulsants, narcotic analgesics, anaesthetics, sedative antihistamines, barbiturates, MAO inhibitors and other antidepressants)
  • Alcohol (enhanced sedative effect; not recommended)
  • Antacids (diazepam peak concentrations ~30% lower)

Clinical monograph

How it works

It potentiates the inhibitory neurotransmitter GABA at the GABA-A receptor, increasing the frequency of chloride channel opening to produce anxiolytic, sedative, anticonvulsant and muscle-relaxant effects.

Prescribing in practice

  • Risk of dependence, tolerance and withdrawal restricts use to the shortest possible duration; avoid abrupt cessation and taper gradually.
  • Combination with opioids or other CNS depressants markedly increases the risk of profound sedation, respiratory depression and death.
  • Use cautiously in the elderly, in respiratory impairment and in hepatic impairment, where the prolonged half-life increases accumulation.

Monitoring

Monitor for excessive sedation, signs of dependence and respiratory depression, particularly in the elderly and those on other CNS depressants.

Counselling the patient

  • May impair driving and skilled tasks, especially when combined with alcohol.
  • Do not stop suddenly after regular use as withdrawal symptoms can occur.
  • Avoid alcohol and other sedating medicines while taking this drug.

Evidence & guidelines

Benzodiazepine use is well established, and NICE guidance recommends restricting it to short-term use because of dependence risk.

Reference: NICE NG217 (Epilepsies in adults 2022); APLS Pathway; MHRA Drug Safety Update Apr 2020 (benzodiazepines + opioids); SmPC Diazemuls; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Drugs
Same class
Pathways
Same specialty