Which medication class should be avoided in older adults with syncope due to orthostatic hypotension?

• A. Antipsychotics
• B. Cholinesterase inhibitors
• C. Non-selective peripheral alpha-1 blockers
• D. TCAs

Answer: (C)

Blocking the body's ability to constrict blood vessels leads to orthostatic hypotension. Non-selective peripheral alpha-1 blockers prevent reflex vasoconstriction in response to standing, causing a significant drop in blood pressure and increasing the risk of syncope in older adults. Because this effect is the most direct and reliable way to provoke fainting in this scenario, avoid this class in someone with syncope due to orthostatic hypotension. Other listed drug classes can affect blood pressure or cause fainting through other mechanisms, but their impact on orthostatic drops is less consistent or direct compared to non-selective alpha-1 blockers.