Drug reference

Thiopental

Sedative-Hypnotic · Anticonvulsant, General Anesthetic

Also known as Thiopental sodium, Thiopentone sodium

Sedative-HypnoticAnticonvulsant, General Anesthetic

CDSCO approved

EXCRETION

—

not curated

INTERACTIONS

9 major

incl. contraindicated

PREGNANCY

—

not curated

Top interactionssee all 9 →

SuccinylcholineContraindicatedTextbookKDT 7e · p347-359
Acidic DrugsSevereTextbookG&G 14e · p476
EthanolSevereDatabaseDDInter
IsocarboxazidSevereDatabaseDDInter

Mechanism

Thiopental is an ultra-short-acting barbiturate that binds to GABA-A receptors, increasing the duration of chloride channel opening and at anesthetic doses directly activating the channel. Its ultra-short clinical effect after a single IV bolus (5-10 minutes) is due not to metabolism but to rapid redistribution from the highly perfused brain to lean body mass and then to adipose tissue — a classic pharmacokinetic principle. It has no analgesic activity and actually lowers the pain threshold at sub-anesthetic doses.

Indications

Status epilepticus (only if other measures fail)Anaesthesia of short durationReduction of raised intracranial pressure if ventilation controlledintravenous anesthesiaInduction and maintenance of anesthesiaPreoperative sedationEmergency management of seizuresIntracranial pressureanesthetic induction

Dosing

Adult: Status epilepticus (only if other measures fail): By slow intravenous injection: 75–125 mg for 1 dose as a 2.5% (25 mg/mL) solution; OR, initially 100–150 mg over 10–15 seconds usually as a 2.5% (25 mg/mL) solution, followed by 100–150 mg after 0.5–1 minute if required (for fit and premedicated adults). Alternatively, initially up to 4 mg/kg.…
Geriatric: Debilitated patients or adults over 65 years may require a lower dose or increased administration time for Status epilepticus and Anaesthesia of short duration.
Max dose: Max per dose: 500 mg (for 4 mg/kg alternative dosing for Status epilepticus and Anaesthesia of short duration)

Pharmacokinetics

Onset

Rapid (after intravenous injection)

Duration

duration of action after single bolus limited by redistribution (usually emerge within 10 min); prolonged infusions can cause unconsciousness lasting several days

Half-life

3-8 hours (elimination after single dose)

Protein binding

Little binding to brain constituents

Metabolism

Slow actual clearance

Contraindications

Acute porphyrias
Myotonic dystrophy
patients with acute intermittent or variegate porphyria

Side effects

Common

dose-dependent decrease in blood pressureincreased heart rate (compensatory)respiratory depressionwheezing (higher incidence in asthmatics, attributed to histamine release)

Serious