A doctor should be consulted at once if any of the following severe side effects are experienced by a patient: abnormal or rapid heart rate, arm or leg tremors, shaking, abdominal pain, bloody urine, chest pain, diarrhea, facial swelling, side pain, skin rashes, chest tightness, or hives. In addition, users may experience the following minor adverse reactions: body aches, sinus congestion, fevers, swollen glands, changes in the voice, painful urination, earaches, muscle pain, skin redness, or swelling of the ear.