Which of the following is not listed among the adverse effects of anticholinergic therapy?

• A. Dry mouth
• B. Confusion
• C. Weight gain
• D. Urinary retention

Answer: (C)

Anticholinergic drugs work by blocking muscarinic receptors, which reduces parasympathetic activity and effects on secretions and smooth muscles. The most typical adverse effects come from this blockade: dry mouth from reduced salivation, confusion or delirium from central nervous system muscarinic blockade, and urinary retention from relaxation of the detrusor muscle with increased sphincter tone. Weight gain does not arise from this mechanism in a direct, predictable way, so it isn’t usually listed among the adverse effects. Therefore, weight gain is the best choice for not being listed, while the others reflect classic anticholinergic effects.