Drug-induced disorders of the stomach and duodenum

Adverse drug reactions occur in 10-20% of hospitalized patients, leading to a fatal outcome in approximately two per 10,000 surgical and nine per 10,0 00 medical patients [1-3]. The gastrointestinal (GI) tract is involved in 2 0-40% of drug-induced complications [4]. Although any segment can be affect ed, the stomach and duodenum are the principal sites of direct mucosal inju ry by orally administered medications. Adverse drug reactions have been classified into two major types. Type A re presents predictable pharmacologic side effects, which are responsible for nearly 80% of reported GI complications [3]. These include functional distu rbances such as vomiting, diarrhea, and constipation as well as dyspepsia a nd various other GI symptoms related to direct gastroduodenal irritation by ingested drugs [3-6]. Type B indicates unpredictable idiosyncratic reactio ns, such as anaphylactic shock and Henoch-Schonlein purpura. An understanding of the pharmacodynamics of various drugs can assist in rec ognition of their potential complications. Otherwise, the clinical and radi ographic findings may be difficult to distinguish from those caused by infl ammatory, infectious, or neoplastic processes. The purpose of this article is to review the spectrum of drug-induced gastroduodenal injuries and illus trate their radiologic features.