Which of the following is a remembered adverse effect of anticholinergic drugs like atropine?

Which of the following is a remembered adverse effect of anticholinergic drugs like atropine?

• A. Decreased GI peristalsis
• B. Increased GI peristalsis
• C. Diarrhea
• D. Muscle tremor

Answer: (A)

Anticholinergic drugs block muscarinic receptors, reducing parasympathetic activity. In the gastrointestinal tract, parasympathetic input normally promotes peristalsis; when this is blocked, gut motility slows down. That slowing of movement is the remembered adverse effect you’d expect with atropine-like drugs, leading to constipation or decreased intestinal transit.

Increased GI peristalsis or diarrhea would imply added parasympathetic stimulation, which these drugs do not cause. Muscle tremor isn’t a typical remembered adverse effect of anticholinergics; they’re more commonly associated with dry mouth, blurred vision, tachycardia, urinary retention, and confusion in higher doses.