**Question:** The drug that causes fall in elderly patients with postural hypotension is:-

A. Calcium channel blockers
B. Anticholinergics
C. Central nervous system stimulants
D. Alpha-adrenergic agonists

**Core Concept:**
Postural hypotension, also known as orthostatic hypotension, is a decrease in blood pressure when a person stands up or changes position, resulting in dizziness, lightheadedness, and even syncope (fainting). This condition is more common in the elderly due to age-related factors such as reduced cardiac output, venous pooling, and baroreceptor sensitivity.

**Why the Correct Answer is Right:**
Calcium channel blockers are a type of medication that work by blocking calcium ions from entering cardiac and smooth muscle cells, leading to vasodilation (widening of blood vessels) and reduced cardiac contractility. This results in a decrease in blood pressure, making calcium channel blockers a potential cause of postural hypotension in elderly patients.

**Why Each Wrong Option is Incorrect:**

B. Anticholinergics (e.g., antispasmodics) are medications that block the action of acetylcholine, a neurotransmitter involved in muscle contraction and gastrointestinal motility. While anticholinergics can cause dry mouth, blurred vision, constipation, and urinary retention, they do not directly affect blood pressure or contribute to postural hypotension.

C. Central nervous system stimulants (e.g., amphetamines) increase sympathetic nervous system activity, potentially leading to tachycardia (rapid heart rate), hypertension (high blood pressure), and vasoconstriction (narrowing of blood vessels). These medications are not a cause of postural hypotension in elderly patients.

D. Alpha-adrenergic agonists (e.g., ephedrine) increase sympathetic nervous system activity, leading to vasoconstriction (narrowing of blood vessels) and increased cardiac output. These medications can lead to hypertension and are not a cause of postural hypotension in elderly patients.

**Clinical Pearl:**
Postural hypotension in elderly patients is more often seen with medications that cause vasodilation (widening of blood vessels) and reduced cardiac output. Calcium channel blockers, due to their vasodilatory effect, are the correct answer. Anticholinergics, central nervous system stimulants, and alpha-adrenergic agonists are not the correct answers because they do not cause vasodilation and reduced cardiac output, leading to postural hypotension.