Background: Trimethoprim is the antibiotic of choice for treating uncomplicated community acquired urinary tract infections. However, before prescribing any drug it is vital to obtain a detailed drug history to exclude possible drug allergy.
Objective: We present the case of a fatal adverse drug reaction due to trimethoprim. We discuss some of the problems that led to the patient's death, and consider how to prevent similar events.
Discussion: Re-exposing a patient to a drug suspected of causing an adverse reaction is associated with considerable risk of morbidity and mortality. A detailed history is vital to correctly diagnose drug allergies but, even so, it is not always possible to identify the causative agent. Following an adverse drug reaction, health professionals must take appropriate steps to avoid inadvertently re-prescribing the culprit drug. This is essential to avoid the tragic outcome highlighted in this case.