Final answer:
The 60-year-old patient's dizziness and near-syncopal events are likely caused by Metoprolol, a β-blocker that can reduce heart rate and blood pressure.
Step-by-step explanation:
The 60-year-old patient experiencing dizziness and near-syncopal events may be experiencing side effects from one of her medications. Among the listed medications, Metoprolol is the most likely suspect. Metoprolol is a β-blocker that can cause side effects like dizziness by blocking the β1-receptors, which in turn can lead to a decrease in heart rate and a reduction in blood pressure, possibly resulting in dizziness or near-syncopal events.