Can cause anxiety
 restlessness
 agitation and increased salivation
Sleepiness or sleeplessness
 involuntary movements
 drowsiness
 dizziness
 and seizures
constipation
 nausea
 vomiting
 dry mouth and increased appetite
 abnormal heart rhythm
 slow heart rate and low blood pressure
Impotence
 weight gain
 fever
 raised liver enzyme level
 and allergic reaction.