The goal of anti-epileptic treatment is to prevent the occurrence of seizures by maintaining an effective dose of one or more anti-epileptic drugs (AEDs) and keeping any adverse effects to a minimum.

Dose regimen

Typical regimens:

• Carbamazepine: Initially 100-200mg once or twice daily, increased slowly to usual dose of 0.8 -1.2g daily in divided doses.
• Gabapentin: 300mg on day 1, then 300mg twice daily on day 2, 300mg three times daily on day 3, then increased according to response in steps of 300mg daily (in three divided doses) to maximum 2.4g daily. Usual range 0.9 -1.2g daily.
• Sodium valproate: Initially 600mg daily in two divided doses, preferably after food, increased by 200mg daily every three days to maximum 2.5g daily in divided doses. Usual maintenance dose 1-2g daily (20 -30mg/kg daily).

Patient’s knowledge of the medicine’s use

AEDs work by affecting the chemicals in the brain that are involved in sending signals to the nerves. The precise mechanism of action is unclear.

• Patients on certain anti-epileptics and their carers should be told how to recognise signs of blood, hepatic and skin disorders and advised to seek immediate medical attention if symptoms such as fever, sore throat, rash, mouth ulcers, bruising or bleeding develop. Drugs potentially liable to cause some of these disorders include carbamazepine, oxcarbazepine, ethosuximide, lamotrigine, phenytoin and sodium valproate.

Is the medicine working?

• Is the patient taking the medication correctly and maintaining compliance?
• If the patient is not seizure-free despite taking the maximum-tolerated dose of an AED, this would indicate that the AED is not working. Subsequent therapy with two or more AEDs may be tried in an attempt to control seizure occurrences.
• Pharmacist should ensure the patient consistently receives the same brands of AEDs.

Side-effects

Typical side-effects of most anti-epileptics include nausea, vomiting, constipation, diarrhoea, drowsiness, headache and mood changes.

Monitoring

• Monitoring may be required when anti-epileptic therapy is initiated, after dosage adjustments, to identify non-compliance or to identify inappropriate dosage.
• Patients on vigabatrin should have visual field testing before treatment and at six-monthly intervals.
• Patients on topiramate who develop any eye symptoms, particularly in the first few weeks of treatment, should immediately see their doctor.
• Patients on phenytoin need regular plasma concentration monitoring.
• Patients on sodium valproate need liver function tests before therapy and during the first six months.

Lifestyle tips

• Advise patient to keep a seizure diary to identify and avoid any trigger factors.

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• Emphasise importance of complying with medication.
• Inform patients of the common factors that can increase risk of seizures, such as stress, lack of sleep, flickering or flashing lights, and certain medications and supplements (St John’s Wort has been shown to interact with certain AEDs). 

• Non-drug approaches which may be tried include relaxation and CBT (cognitive behaviour therapy).