Uncommon side effects Skin rash, itchy skin, indigestion, shortness of breath, muscle cramps, altered bowel habit, muscle or joint pain, back pain, chest pain, mood changes, tremor, visual disturbances, tinnitus, hypotension, difficulty in breathing, taste perversion, runny nose, increased need to urinate, dry mouth, thirst, loss of pain sensation, increased sweating, fainting, weakness, enlargement of breasts in men, impotence, weight increase, weight decrease.