What are the potential side effects of antiepileptic drugs in children, and how should I monitor for them?

Antiepileptic drugs (AEDs) in children can cause a range of potential side effects including serious skin reactions (notably with phenytoin, carbamazepine, oxcarbazepine, and eslicarbazepine acetate), decreased bone mineral density leading to osteomalacia (with carbamazepine, phenytoin, primidone, and sodium valproate), and possible neurodevelopmental risks associated with sodium valproate, especially in men around conception and in women during pregnancy.

Other side effects include sedation, tremor, gait disturbance, blood and liver disorders (notably with valproate), and interactions affecting hormonal contraceptive effectiveness (with carbamazepine, oxcarbazepine, phenytoin, topiramate, and lamotrigine).

Monitoring should be tailored individually but generally includes regular reviews at least annually, with more frequent reviews if there are learning disabilities, drug-resistant epilepsy, high SUDEP risk, serious comorbidities, or use of high-risk AEDs such as sodium valproate.

Specific monitoring for valproate includes baseline and periodic liver function tests, full blood counts, and weight/BMI measurements, with vigilance for signs of blood or liver disorders and immediate cessation if abnormalities occur.

Plasma drug levels are not routinely required unless there is evidence of ineffectiveness, toxicity, or poor adherence.

Families and children should be informed about side effects and involved in agreeing monitoring frequency, with additional support from epilepsy specialist nurses as needed.