Which demographic is particularly vulnerable to adverse drug reactions due to developmental factors?

Infants are particularly vulnerable to adverse drug reactions due to their unique developmental factors. At this stage of life, the body is still developing, and this includes organ function, enzyme activity, and metabolic pathways. Infants possess immature liver and kidney functions, which can significantly alter the pharmacokinetics of medications — including absorption, distribution, metabolism, and excretion. This immaturity can lead to higher plasma concentrations of drugs for longer periods, increasing the risk of toxicity and adverse effects.

Furthermore, infants have a higher body water content and lower body fat compared to adults, influencing how drugs are distributed in the body. Dosing calculations are also more complex in this age group, as they often rely on weight-based formulas that can be prone to error. Additionally, the blood-brain barrier in infants is not fully developed, making them more susceptible to central nervous system effects from medications.

On the other hand, while aged adults may also be at risk for adverse drug reactions due to physiological changes associated with aging, their vulnerabilities are different and typically relate to comorbidities and polypharmacy rather than developmental factors. Adolescents and middle-aged adults face their own challenges in medication safety, but the specific developmental vulnerabilities seen in infants make them the demographic most at