Acute haematologic reaction: Drug or bug?

β-lactams are known to cause haematologic reactions. Cefoperazone is one such β-lactam that is commonly combined with a β-lactamase inhibitor, sulbactam. A review of the available literature suggests that cefoperazone can cause or precipitate haematologic reactions, including anaemia, leucopenia, thrombocytopenia and hypoprothrombinemia. Similarly, Escherichia coli (E. coli) is a commonly encountered organism associated with urinary tract infections and urosepsis, which can also present in a similar. This case report is a description of an elderly patient who harboured E. coli, and was also given cefoperazone-sulbactam, and later developed haematologic reactions.