IV Induction Agent (Barbiturate) Pregnancy: Use with caution — crosses placenta; used for induction at caesarean section in some centres

Thiopental Sodium

Brand names: Intraval Sodium

Adult dose

Dose: 100-150 mg IV over 10-15 seconds (induction); titrate further 50-100 mg boluses to effect

Route: Intravenous

Frequency: Single induction dose

Max: 500 mg total (routine); higher under specialist supervision

Reconstitute to 2.5% solution (25 mg/mL). Reduce dose in elderly, debilitated, or haemodynamically compromised patients (50-75 mg). Ensure IV access confirmed — arterial injection causes severe vasospasm

Paediatric dose

Dose: 5-7 mg/kg IV (induction) mg/kg

Route: IV

Frequency: Single induction dose

Max: 500 mg

Neonate: 2-3 mg/kg. Child 1 month to 12 years: 5-7 mg/kg. Child 12-17 years: 3-5 mg/kg

Dose adjustments

Renal

Reduce dose — protein binding reduced; more free drug available

Hepatic

Use with caution — metabolism impaired; prolonged recovery

Paediatric weight-based calculator

Patient weight (kg)

Neonate: 2-3 mg/kg. Child 1 month to 12 years: 5-7 mg/kg. Child 12-17 years: 3-5 mg/kg

Clinical pearls

Absolute contraindication in porphyria — thiopental induces haem synthesis, precipitating acute porphyric crisis; use propofol or ketamine instead
Intra-arterial injection is a serious complication — causes intense vasospasm, thrombosis, and potentially limb ischaemia; always confirm IV placement before injection; treat with vasodilators and sympathetic blockade
Largely superseded by propofol for routine anaesthesia but retained for specific indications: rapid sequence induction (with suxamethonium), raised ICP (cerebral protection), and status epilepticus refractory to other agents
Context-sensitive half-time increases dramatically with repeat doses — not suitable for infusion; single induction bolus only in most settings
Alkaline solution (pH 10.5) — incompatible with most drugs; flush line before and after

Contraindications

Porphyria (absolute — can precipitate acute attack)
Absence of airway equipment and resuscitation facilities
Allergy to barbiturates

Side effects

Respiratory depression and apnoea (universal)
Hypotension
Laryngospasm
Tissue necrosis (extravasation or intra-arterial injection)
Anaphylaxis (rare)
Histamine release

Monitoring

Airway and SpO2
Blood pressure
Level of consciousness
IV site (extravasation)

Reference: BNFc; BNF 90; AAGBI; Intraval Sodium SPC; BMA/RPS BNF. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways