Which medication should be used with caution in older adults due to reduced kidney excretion?

The correct answer highlights the need for careful management of digoxin in older adults due to the fact that it is primarily excreted by the kidneys. As individuals age, there is often a natural decline in renal function, which can lead to an accumulation of digoxin in the body. This increases the risk of toxicity, which can manifest in symptoms such as nausea, vomiting, confusion, and cardiac arrhythmias.

Therefore, it is crucial for healthcare providers to monitor kidney function closely when prescribing digoxin to older patients, adjusting dosages as necessary to avoid adverse effects. While the other medications listed may also require caution in certain situations, digoxin's narrow therapeutic index and reliance on renal excretion make it particularly sensitive to changes in kidney function, necessitating more stringent monitoring and dosage adjustments in the older population.