Which age-related change can affect oral drug absorption in the elderly?

• A. Decreased gastric blood flow reduces absorption.
• B. Gastric pH is often decreased, affecting absorption.
• C. Mucosal edema reduces absorption.
• D. Intravenous drugs have slower absorption than oral

Answer: (B)

Age-related changes in the stomach environment can change how well an oral drug is absorbed. The most impactful factor is gastric pH. As people age, stomach acid production often decreases, making the stomach less acidic. That higher pH can reduce the dissolution of drugs that require an acidic environment to dissolve properly, leading to less drug being absorbed into the bloodstream. So, shifts in gastric pH directly influence oral drug absorption in the elderly, which is why this factor is the best fit. Other options reference factors that are less consistently linked to aging or pertain to routes of administration rather than changes in the stomach that affect absorption.