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