Irritability, nervousness, restlessness, insomnia, abnormal dreams, migraine, psychomotor hyperactivity (restlessness associated with increased activity), dizziness, somnolence (tiredness), abdominal pain, constipation, dry mouth, hyperbilirubinaemia (changes in the composition of your blood which could cause yellowing of the skin or eyes (jaundice), hyperhidrosis (excessive sweating), asthenia (feeling of weakness) and weight increase.