Which groups are at increased risk for adverse drug events?

• A. The very young, the very old, and those with serious illnesses
• B. Healthy middle-aged adults
• C. Teenagers on single medications
• D. Adults with no comorbidities

Answer: (A)

Adverse drug events are more likely when patient factors alter how a drug is processed and how the body responds to it. The very young and the very old have developing or aging organ systems that handle medications differently, plus they often have multiple medicines or comorbidities that raise interaction and dosing risks. In young patients, immature liver and kidney function, plus growth-related dosing challenges, can lead to drug accumulation or unpredictable effects. In older adults, reduced renal and hepatic clearance, changes in body fat and lean mass, and polypharmacy with multiple chronic conditions increase the likelihood of drug–drug interactions and adverse reactions. When someone has serious illness, organ impairment, or requires complex regimens, those same factors—diminished clearance, higher vulnerability to side effects, and potential for inappropriate dosing—heighten ADE risk. By contrast, healthy middle-aged adults, teenagers on a single medication, or adults without comorbidities generally have more stable pharmacokinetics and fewer interacting medications, making adverse events less likely.