Key investigations

Key investigations for lamotrigine poisoning are:

• electrocardiogram (ECG)
• serum electrolyte, urea and creatinine concentrations.

In patients taking lamotrigine therapeutically, also check:

• full blood count—to detect eosinophilia
• liver biochemistry—to detect hepatitis.

Lamotrigine serum concentrations are not widely or rapidly available and are not useful in the management of poisoning.