Hypotension, confusion, fever, lethargy, seizure, pruritus, rash, urticaria, abdominal pain, black or hairy tongue, diarrhoea, flatulence, nausea, oral candidiasis, pseudomembranous colitis, stomatitis, vomiting, agranulocytosis, bone marrow depression, eosinophilia, granulocytopenia, haemolytic anaemia, leucopenia, neutropenia, thrombocytopenia, increased alkaline phosphatase, ALT and AST, hepatotoxicity, thrombophlebitis, arthralgia, myalgia, myoclonus, hematuria, interstitial nephritis, proteinuria, renal insufficiency, renal tubular damage, bronchospasm, laryngeal oedema, laryngospasm, sneezing, wheezing, angioedema, allergic reaction, serum sickness-like reaction. Potentially Fatal: Anaphylaxis.