Which statement best differentiates anticholinergic toxicity from cholinergic (organophosphate) toxicity?

Which statement best differentiates anticholinergic toxicity from cholinergic (organophosphate) toxicity?

• A. Anticholinergic causes increased salivation; cholinergic reduces
• B. Anticholinergic causes dry skin and dilated pupils; cholinergic causes salivation, lacrimation, urination, defecation, and miosis
• C. Both types cause miosis
• D. Anticholinergic causes nausea and GI irritation

Answer: (B)

The key idea is how these toxicities affect muscarinic receptors in the body. Anticholinergic toxicity blocks muscarinic receptors, which reduces secretions and causes pupil dilation, leading to dry skin, dry mucous membranes, and mydriasis. In contrast, cholinergic (organophosphate) toxicity ramps up acetylcholine activity at muscarinic receptors, producing excess secretions and constricted pupils—classic SLUD symptoms: salivation, lacrimation, urination, defecation, and miosis. That’s why the statement describing anticholinergic effects as dry skin with dilated pupils, and cholinergic effects as prominent secretions plus miosis, best differentiates the two. The other options either reverse these effects or state a feature (like miosis) that applies to cholinergic toxicity but not to anticholinergic toxicity.

The key idea is how these toxicities affect muscarinic receptors in the body. Anticholinergic toxicity blocks muscarinic receptors, which reduces secretions and causes pupil dilation, leading to dry skin, dry mucous membranes, and mydriasis. In contrast, cholinergic (organophosphate) toxicity ramps up acetylcholine activity at muscarinic receptors, producing excess secretions and constricted pupils—classic SLUD symptoms: salivation, lacrimation, urination, defecation, and miosis.

That’s why the statement describing anticholinergic effects as dry skin with dilated pupils, and cholinergic effects as prominent secretions plus miosis, best differentiates the two. The other options either reverse these effects or state a feature (like miosis) that applies to cholinergic toxicity but not to anticholinergic toxicity.