agitated, anxiety, unusual dreams, lack of appetite, dizziness, feeling sluggish, numbness, feeling the heart pumping in the chest, stomach pain, heartburn or indigestion, increased sweating, decreased sex drive, falls and fatigue. Uncommon side effects may include suicidal thoughts, grinding or clenching the teeth, feeling disorientated, lack of motivation, sensation of restlessness, feeling nervous, difficulty concentrating, lack of coordination, poor sleep quality, fast or irregular heart beat, night sweats, sensitivity to sunlight, muscle tightness or twitching, weight gain or weight loss, chest pain, feeling cold first shivering. Rare side effects may include suicidal behaviour, mania (overactivity racing thoughts and decreased need for sleep), hallucinations, aggression and anger, 'serotonin syndrome' (a rare reaction which may cause feelings of great happiness, drowsiness, clumsiness, restlessness, feeling of being drunk either fever, sweating or rigid muscles).