Vigabatrin


  Issues for Surgery


Precipitation of rebound seizures or status epilepticus if omitted.


  Advice in the Perioperative period


Elective and Emergency Surgery

Continue.

Patients should be advised to take their regular medications on the day of surgery1, 2, 3.

Abrupt withdrawal of any anticonvulsant drug should be avoided1

Confirm with the patient if they need to be maintained on a specific manufacturer’s product (see Further Information).

Post-operative Advice

Regular dosing of the patient’s usual oral medication should be re-established as early as possible post-operatively2, 3.

If patients are unable to take their regular oral medication post-operatively, consider using the oral powder sachets via the rectal route [unlicensed use]1. The rectal dose and frequency should be the same as the established oral dose. Alternatively, seek the advice of a Neurologist to determine an appropriate medication, dose, route and frequency.


  Interaction(s) with Common Anaesthetic Agents


None1, 4, 5, 6.

For general information regarding the use of anaesthetic agents in patients with epilepsy – see Antiepileptics – A General Overview.


  Interaction(s) with other Common Medicines used in the Perioperative Period


None1, 4, 5, 6.

For general information regarding the use of antiemetics in patients with epilepsy – see Antiepileptics – A General Overview’.


  Further Information


MHRA/CHM Advice: Antiepileptic Drugs: updated advice on switching between different manufacturer’s products (November 2017)1

Vigabatrin is a category 3 antiepileptic, hence it is usually unnecessary to ensure that patients are maintained on a specific manufacturer’s product unless there are specific concerns such as patient anxiety, and risk of confusion or dosing errors. (For more information see Antiepileptics – A General Overview).

Liver Function Tests (LFTs)

Vigabatrin may lead to a decrease in measured plasma activity of alanine aminotransferase (ALT) and to a lesser extent, aspartate aminotransferase (AST). The magnitude of suppression for ALT has been reported to vary between 30% and 100%. Bear this in mind if it is necessary to check LFTs pre-operatively as these liver tests may be quantitatively unreliable in patients taking vigabatrin6.


  References


  1. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press http://www.medicinescomplete.com [Accessed 30th June 2019]
  2. Perks A, Cheema S, Mohanraj R. Anaesthesia and epilepsy. BJA: British Journal of Anaesthesia. 2012; 108(4):562-571
  3. Carter EL, Adapa RM. Adult epilepsy and anaesthesia. BJA Education. 2015; 15(3):111-117
  4. Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 20th July 2019]
  5. Vigabatrin. In: Brayfield A (Ed), Martindale: The Complete Drug Reference. London: The Royal Pharmaceutical Society of Great Britain. http://www.medicinescomplete.com [Accessed 20th July 2019]
  6. Summary of Product Characteristics – Sabril® (vigabatrin) 500mg film-coated tablets. SANOFI. Accessed via www.medicines.org.uk 20/07/2019 [date of revision of the text November 2018]