This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pharmacodynamics, Subject name: Pharmacology
A drug is more likely to cause toxicity in elderly patients due to all of the following reasons EXCEPT: 
Select and explain. 
A. decreased renal excretion of drugs, B. decreased hepatic metabolism, C. increased receptor sensitivity, D. decreased volume of distribution
D: decreased volume of distribution
Answer: D: decreased volume of distribution 
Explanation: Ans. is 'd' ie decreased volume of distribution Volume of distribution is increased with aging. This leads to decreased elimination of the drug and hence increased toxicity.Other changes seen with aging which lead to increased toxicity of drugsincreased sensitivity of the target organs*decreased renal excretion of drugs *decreased hepatic metabolism of drugs*body mass is decreased*