Which statement about obesity and fat-soluble drug dosing is true?

• A. Obesity leads to reduced drug distribution
• B. Obesity increases renal clearance of fat-soluble drugs
• C. Obesity leads to prolonged exposure due to adipose storage
• D. Obesity has no effect on fat-soluble drug pharmacokinetics

Answer: (C)

Lipophilic drugs readily partition into adipose tissue, so in obesity the expanded fat mass acts as a larger reservoir. This increases the volume of distribution for fat-soluble medications, meaning more drug is stored away in fat and released slowly back into circulation. The result is a longer elimination phase and prolonged systemic exposure, which is why this statement is true for obesity and fat-soluble drug dosing. In contrast, fat-soluble drugs are not typically characterized by reduced distribution or by a straightforward increase in renal clearance; there is indeed an effect on pharmacokinetics due to adipose storage, which makes the other options inaccurate.