How do medications typically affect older patients in terms of drug efficacy?

The correct choice highlights that drugs do not last as long in older patients due to decreased lipid solubility. As people age, their body composition changes, often leading to an increase in body fat and a decrease in total body water. This change influences the distribution of drugs that are lipid-soluble versus those that are water-soluble.

For lipid-soluble medications, increased body fat may initially suggest that these drugs could persist longer in the system due to a larger volume of distribution. However, in older patients, the effectiveness and half-life of these medications can be unpredictable due to factors like altered hepatic and renal function, which can diminish the metabolism and clearance of drugs.

As for water-soluble drugs, the decrease in total body water in older adults can lead to higher concentrations of the drug in the bloodstream, which may increase the drug's effects, but this can also lead to toxicity if doses are not appropriately adjusted. This understanding of how drug metabolism and efficacy change with age is crucial for tailoring safer and more effective medication strategies for older patients.