Adverse Drug Effects Involving the Gastrointestinal System (Pharmacist Perspective)

Abstract

Advances in pharmacotherapy have greatly contributed to an increased life expectancy of the adult population. As a result, an ever increasing proportion of the global population now consists of older adults who require ongoing pharmacological management of chronic disease states. While pharmacotherapy can significantly reduce the morbidity and mortality associated with chronic diseases, medications and complex regimens can lead to unintended effects, especially in older adults. The majority of adverse drug effects in the gastrointestinal tract manifest as nausea and vomiting, diarrhea, peptic ulcer, and gastrointestinal bleeding. Older adults are especially prone to experiencing these adverse reactions due to physiological changes in the gastrointestinal tract changes that occur with aging. This chapter discusses adverse drug reactions that involve the gastrointestinal tract, including nausea, vomiting, anorexia, diarrhea, xerostomia, infections, pancreatitis, colonic injury, as well as adverse effects consequent to enteral tube medication administration. Clinicians should be able to recognize medication-induced disorders to aid in diagnosis in an older patient presenting with gastrointestinal manifestations. Early recognition of adverse drug reactions can prompt the clinician to adjust the medication regimen or discontinue the causal agent, which in most cases is sufficient for the complete resolution of symptoms. This approach can prevent unnecessary initiation of pharmacotherapy to treat drug-induced symptoms and avoid perpetuating the cycle of polypharmacy in the older adult.

Keywords