Facial flushing and itching, w/ or w/o a rash, flu-like syndrome characterised by episodes of fever, chills, headache, dizziness, bone pain, shortness of breath, and malaise; GI adverse effects (e.g. nausea, vomiting, anorexia, diarrhoea, epigastric distress), pseudomembranous colitis, eosinophilia, leucopenia, haemolytic anaemia; alterations in kidney function and renal failure, menstrual disturbances, oedema, myopathy, muscular weakness; orange-red discolouration of the urine, faeces, sweat, saliva, sputum, tears, and other body fluids; Rarely, eye irritation and visual disturbances, anaphylaxis or shock. Potentially Fatal: Hepatotoxicity, hypotension, sinus tachycardia, ventricular arrhythmias, seizures and cardiac arrest, thrombocytopenia and purpura.