Add-on therapy for focal seizures with or without secondary generalisation. Possible side effects: Dizziness, sleepiness, loss of or increased appetite, aggression, anger, anxiety, confusion, unsteadiness, speech difficulties, balance disorder, irritability, blurred or double vision, vertigo, nausea, back pain, walking difficulty, fatigue, weight gain, and risk of falling. Report severe reactions, such as a skin rash, to your doctor.