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Thiopental Intravenous for Adults

Who can administer

Administration RESTRICTED - see Appendix 1

Important information

  • Stored as a controlled drug in GUH
  • For use by anaesthetists only
  • Extravasation can cause local tissue necrosis and severe pain - use central line or large peripheral line (ref 1).
  • Resite cannula at first signs of inflammation
  • Accidental intra-arterial injection causes severe arterial spasm and an intense burning pain around the injection site (ref 1)
  • For Y-site compatibility see below

Available preparations

Thiopental 500mg vial

Reconstitution

Water for injection

20ml per 500mg vial (produces a 25mg/ml (2.5%) solution)

Methods of intravenous administration

Bolus intravenous injection

  • Administer required dose over 10 to 15 seconds(ref 1) (20 seconds for Thiopentone Inresa brand (ref 5))
  • However it is recommended to administer incremental doses rather than one bolus dose in order to achieve greater control and better recovery (ref 4)

For administration by other routes - see Further Information

Dose in adults

Use in anaesthesia

  • It is recommended to administer incremental doses rather than one bolus dose in order to achieve greater control and better recovery (ref 4)
  • A test dose of 25 to 75mg can precede the main administration (ref 1,2). Monitor for at least 60 seconds to assess tolerance or unusual sensitivity to the drug(ref 1)
  • Give 100 to 150 mg over 10 to 15 seconds(ref 2,3)
  • A repeat dose of 100 to 150mg may be given after 30 to 60 seconds(ref 2,3)
  • No fixed dosage recommendations can be given since the dose will need to be carefully adjusted according to response. Factors such as age, sex, weight should be taken into account(ref 4)
  • Maximum dose 500mg(ref 3)

Use in convulsive states (ref 3,4)

  • Give 75 to 125mg as soon as possible after the convulsion begins
  • Further doses may be required

Use in neurological patients with raised intracranial pressure (ref 2)

  • Intermittent bolus doses of 1.5 to 3mg/kg may be given to reduce elevations of intracranial pressure if controlled ventilation is provided

Reduced doses may be required in the following patients (ref 4)

  • Elderly
  • Patients pre-medicated with narcotic analgesics
  • Hepatic impairment
  • Shock
  • Dehydration
  • Severe anaemia
  • Hyperkalaemia
  • Toxaemia
  • Myxoedema
  • Other metabolic disorders
  • Severe renal impairment (ref 3)

Increased doses may be required in the following patients (ref 4)

  • Patients with a history of drug or alcohol abuse

Monitoring

  • Severe or refractory hypokalaemia during the infusion has been reported, severe rebound hyperkalaemia may occur after administration has stopped (ref 1)
  • Endotrachael intubation equipment, oxygen and resuscitation equipment should be readily available (ref 1)
  • Monitor blood pressure (ref 1), respiratory function
  • Monitor injection site (can cause extravasation)

Further information

Rectal administration (ref 4)

  • Give 25 to 45mg/kg dissolved in 25ml water.
  • Anaesthetic effects are usually seen within 10 minutes of administration

Storage

  • Controlled drug
  • Do not store above 250C

References

1: Injectable medicines guide, downloaded from Medusa 11th Jan 2023

2: Martindale- downloaded from Medicinescomplete 12th Jan 2023

3: BNF- downloaded from Medicinescomplete 11th Jan 2023

4:.SPC March 2019 (no longer marketed but SPC on file)

5: Thiopentone Inresa SPC 06/09/2014

Search synonym thiopentone

Therapeutic classification

Barbiturate

IV Guide Type