AGE-RELATED-CHANGES IN THE GASTROINTESTINAL SYSTEM - EFFECTS ON DRUG-THERAPY

Although there are many changes in the gastrointestinal tract with agi ng, only those in the liver substantially influence blood concentratio ns and clearance of drugs. The liver mass, overall function, and blood flow decrease approximately 1 % per year after age 40 to 50 years, an d accordingly, the hepatic metabolism or clearance of drugs decreases in this proportion. The sensitivity of the gastrointestinal tract to u sual concentrations of drugs is increased, and this, in part, accounts for the increased frequency of adverse drug reactions in elderly pati ents.