 Children and adults differ significantly in terms of how they respond to medications due to their unique physiology and anatomy. Children have lower gastric pH and emptying times, slower intestinal transit times, and immature secretions and activities of bile and pancreatic fluids, which can all affect the absorption of medicines. Additionally, children have less total body water than adults, which can lead to higher concentrations of certain drugs in the bloodstream. This can cause increased side effects and toxicity. Furthermore, children's liver and kidney functions are not fully developed yet, so they metabolize drugs differently from adults. These differences in drug metabolism can lead to decreased efficacy of some medications in children. This article was authored by Jose T. Ramos, Marta Arteida, Pilar Tejada, and others.