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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