Oxcarbazepine


  Issues for Surgery


Precipitation of rebound seizures or status epilepticus if omitted.


  Advice in the Perioperative period


Elective and Emergency Surgery

Continue - consider checking sodium levels pre-operatively (see Further Information).

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.

Oxcarbazepine is only available as oral preparations. If patients cannot resume their usual oral medication post-operatively, the advice of a Neurologist should be sought to determine the most appropriate antiepileptic preparation, dose, route and frequency to be used.

Monitor renal function and electrolytes, particularly sodium (see Further Information).


  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


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

Antimicrobials

A case report describes a patient who developed oxcarbazepine toxicity when given concomitant clarithromycin. The clinical significance of this is unknown. Bear the interaction in mind if oxcarbazepine adverse effects (e.g. dizziness, drowsiness and ataxia) develop in a patient also given clarithromycin4.

Whilst single surgical prophylactic doses should not pose a problem, continued post-operative treatment may require close monitoring. Consult current product literature.


  Further Information


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

Oxcarbazepine is a category 2 antiepileptic, hence the need for continued supply of a particular manufacturer’s product should be based on clinical judgement and consultation with the patient and / or carer taking into account factors such as seizure frequency treatment history, and potential implications to the patient having a breakthrough seizure. Non-clinical factors such as patient anxiety, confusion, potential for dosing errors should also be considered (For more information see Antiepileptics – A General Overview).

Hyponatraemia

Hyponatraemia, usually asymptomatic, has been seen with oxcarbazepine1, 5, 6. The fall in plasma-sodium concentrations appears to be related to the dose of oxcarbazepine5. Monitor sodium levels in patients with pre-existing conditions associated with low sodium levels and in those taking other medications known to interfere with sodium levels e.g. Non-Steroidal Anti-inflammatory Drugs (NSAIDs)5, 6.


  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 30th June 2019]
  5. Oxcarbazepine. In: Brayfield A (Ed), Martindale: The Complete Drug Reference. London: The Royal Pharmaceutical Society of Great Britain. http://www.medicinescomplete.com [Accessed 30th June 2019]
  6. Summary of Product Characteristics – Oxcarbazepine Mylan 600 mg Film-coated Tablets. Generics UK T/A Mylan. Accessed via www.medicines.org.uk 30/06/2019 [date of revision of the text June 2019]