Second-line ASMs and combining ASMs

If seizure control is not achieved with one of the first-line drugs, then, depending on the seizure type and the child-bearing potential of the individual, another ASM will usually be started. The aim is to titrate out the first ASM once seizure control is achieved so the patient is on monotherapy, to help minimise side-effects. Patients may have to try a number of ASMs, however, with many ultimately ending up on two or more. Finding the best combination that suits an individual can be a case of trial and error. Around 30 per cent of people with epilepsy will have drug resistant seizures, although medication can help to reduce frequency and severity. 

Two other medicines that may be prescribed to patients starting on a new ASM are the benzodiazepines, clobazam and/or buccal midazolam. It should be noted that buccal midazolam should always be prescribed by brand (Epistatus or Buccolam) as the carer will have been trained to use one product.

Almost all patients will require initial titration of their ASM and, if being transferred from another drug, there may be a cross-titration as one drug comes out and the other comes in.

If drugs are started once a day before increasing to multiple dosing throughout the day, taking the drug initially at night can be helpful especially if drowsiness or dizziness is likely. This may also be helpful if seizures have been occurring at night. 

As the person moves to twice daily dosing this should ideally be spaced every 12 hours. However, lamotrigine in particular can cause insomnia so asymmetric dosing may be recommended whereby a higher dose is given during the day and a lower dose in the evening. This regimen might be used for other drugs where there are side-effects or when trying to avoid seizures at a particular time of day. 

The use of clobazam and buccal midazalom