NHS Greater Glasgow & Clyde Area Drug and Therapeutics Committee
Greater Glasgow and Clyde Medicines
Medicines Update

PostScript 79 (Jan 2014) Antiepileptic drugs

Antiepileptic drugs (AEDs)

The MHRA issued advice in November 2013 on the appropriateness of generic prescribing of AEDs and when a patient should stay on a particular brand. This initial guidance is directed at all staff across NHSGGC involved in the prescribing, supply and administration of medicines prescribed for the treatment of epilepsy. The need for more detailed guidance is being considered. This advice is only for the management of epilepsy. Patients on AEDs for neuropathic pain do not require specific brand / manufacturer prescribing.

 

Phenytoin, carbamazepine, phenobarbital, primidone

Prescribers should ensure that their patient is maintained on a specific preparation. 

 

All other AEDs being used to treat epilepsy

Though many patients diagnosed with epilepsy will already be maintained on a single brand or formulation, some of these patients will have historically been prescribed medicines generically and will have previously been subject to variance on the manufacturer of the generic preparation supplied. 

 

For levetiracetam, lacosamide, tiagabine, gabapentin, pregabalin, ethosuximide and vigabatrin, it is not necessary to ensure that patients are maintained on a specific product unless there are risks in doing so.

 

Patients prescribed valproate, lamotrigine, perampanel, retigabine, rufinamide, clobazam, clonazepam, oxcarbazepine, eslicarbazepine, zonisamide or topiramate are not required to be maintained on a specific preparation. The prescriber may consider, following discussion at the patient’s next review, that the circumstances require the need for continuity of supply, eg seizure risk.

 

How to maintain patients on a specific brand or manufacturer’s preparation

  • All sectors of care should prescribe and dispense by brand name where it is possible. 
  • For those medicines that are only available as generic medicines, continuity can be managed by detailing the manufacturer of the generic medicine in the prescription.
  • For GP10 prescriptions, some prescribing systems will allow the choice of a particular manufacturer for a generic medicine.  Where this is not possible, the generic manufacturer can be included in the dosing information so that the information is clear both to the pharmacy supplying the medicine and when the patient moves between sectors of care.
  • Liaise with the patient to ensure that they are aware of the need to continue to use the same brand or manufacturer preparation.
  • Liaise with the pharmacy supplying the medicine to ensure continuity of supply of a particular brand or manufacturer preparation.

 

Advice for patients admitted to hospital

Check the Emergency Care Summary and at least one other information source, to determine if the patient’s AEDs are prescribed using a specific manufacturer’s product. If so, transcribe this information onto the Kardex. 

AEDs prescribed generically can be prescribed generically on the Kardex. The exceptions are phenytoin, carbamazepine, phenobarbital and primidone, which must be prescribed using a specific brand or manufacturer’s preparation. Document decisions in the medicines reconciliation process.

 

Good practice points

  • As it will take time to implement the MHRA advice, there will be patients admitted to hospital with AEDs prescribed generically but with risk factors requiring a change to one product. In such cases, it would be good practice to prescribe by brand where possible.
  • Where a particular product is not available, consider the risks and benefits of a switch. Consider using a suitable alternative generic or brand of the same medicine.

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