Confusion, difficulty of breathing, irregular heartbeat, palpitations or chest pain, joint, muscle or tendon pain, nightmares, changes in thought process, redness, blistering, peeling or loosening of skin, including inside the mouth, seizure, severe or watery diarrhea, skin rash, itching, swelling of face or neck, tremor or restlessness, vision changes, vomiting. Constipation or diarrhea, difficulty in sleeping, dizziness or drowsiness, headache, intestinal gas or bloating, nausea or stomach upset.