Hypersensitivity eg, shock; anergia, fatigue, flushing, occasional chest pain, spasticity, syncope, w/drawal symptom; occasional HTN, exacerbation of HTN, hypotension, arrhythmia, palpitation, tachycardia; dizziness, headaches, tremor, occasional hyperkinesis, convulsion, HTN, migraine, exacerbation of migraine, contraction of involuntary muscle, sensory anomaly, stupor, vertigo; bellyache, constipation, diarrhea, dyspepsia, flatulence, dry mouth, nausea, vomiting, occasional dysphagia, melena, tongue edema; anorexia, anxiety, confusion, insomnia, nervousness, drowsiness, amnesia, depersonalization, depression, drug abuse & dependence, mood change, hallucinations, impotence, nightmares, abnormal thoughts; occasional anemia; occasional resp distress syndrome; proteinuria, dysuria, oliguria, urine retention; pruritus, rash, sweating, urticaria; hepatic dysfunction, wt loss, tinnitus, abnormal vision, chilling.