Severe hemorrhagic syndrome due to similarity of drug names.

The names of many drugs look or sound like those of other drugs, which leads to confusion and potentially harmful medication errors. We report a nearly fatal permutation between two drugs including a vitamin K antagonist that resulted in a 68-year-old man being admitted to the emergency department with severe, spontaneous hemorrhagic syndrome. Such problems can be alleviated through actions by regulatory agencies, pharmaceutical manufacturers, health care professionals, and patients.