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 surgery.
Abrupt withdrawal of any anticonvulsant drug should be avoided.
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-operatively.
Ethosuximide 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.
Interactions with common anaesthetic agents
None.
For general information regarding the use of anaesthetic agents in epilepsy patients see Antiepileptics overview.
Interactions with other common medicines used in the perioperative period
For general information regarding the use of antiemetics in epilepsy patients see Antiepileptics overview.
Antimicrobials
Concomitant use of ethosuximide with the following can increase the risk of myelosuppression:
- co-trimoxazole
- linezolid
- trimethoprim
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 for a particular drug (November 2017)
Ethosuximide is a category 3 antiepileptic, hence it is usually unnecessary to ensure that patients are maintained on a specific manufacturer’s product as therapeutic equivalence can be assumed. However, other factors are important when considering if switching is appropriate such as patient anxiety, risk of confusion or dosing errors. For more information see Antiepileptics overview.
Blood dyscrasias
Blood dyscrasias (leucopenia, agranulocytosis, aplastic anaemia and pancytopenia) have been reported with use of ethosuxmide. Patients should be monitored for sign of blood disorders (e.g. fever, mouth ulcers, bruising, or bleeding). Withdrawal of the drug may be necessary and the patient’s neurologist should be consulted to ensure an appropriate management plan.
References
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press http://www.medicinescomplete.com [Accessed 3rd July 2019]
Perks A, Cheema S, Mohanraj R. Anaesthesia and epilepsy. BJA: British Journal of Anaesthesia. 2012; 108(4):562-571
Carter EL, Adapa RM. Adult epilepsy and anaesthesia. BJA Education. 2015; 15(3):111-117
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 30th June 2019]
Ethosuximide. In: Brayfield A (Ed), Martindale: The Complete Drug Reference. London: The Royal Pharmaceutical Society of Great Britain. http://www.medicinescomplete.com [Accessed 3rd July 2019]
Summary of Product Characteristics – Ethosuximide Essential Generics 250mg/5ml Syrup. Essential Pharma Ltd. Accessed via www.medicines.org.uk 03/07/2019 [date of revision of the text April 2019]