Adverse effects

People with developmental disability are susceptible to the same adverse effects of antiepileptic drugs as the general population (see Avoiding adverse effects of antiepileptic drugs); however, if the person has cognitive or communication difficulties, adverse effects may not be recognised or reported.

Some antiepileptic drugs have adverse effects that are particularly relevant to people with developmental disability, for example:

• phenytoin causes gum hypertrophy in approximately 30% of people but is less common with good dental hygiene; people with developmental disability often have poor oral health, making gum hypertrophy more likely and more troublesome
• levetiracetam may stimulate aggression
• sodium valproate can cause weight gain, which can be difficult to manage and contribute to further disability and comorbidity
• topiramate can cause anorexia and significant weight loss, which is concerning if the person has swallowing difficulties or is underweight.

For related management strategies, see:

• Oral and dental health in people with developmental disability
• Challenging behaviour in people with developmental disability
• Nutritional disorders in people with developmental disability (including obesity and underweight).

For advice on when to measure serum concentrations of antiepileptic drugs, see the Neurology guidelines.