After treating for cardiac dysrhythmias, which drug overdose would present with dry mouth and blurred vision?

• A. Lidocaine
• B. Adenosine
• C. Amiodarone
• D. Atropine

Answer: (D)

Dry mouth and blurred vision come from anticholinergic (antimuscarinic) toxicity. Atropine blocks muscarinic receptors, suppressing the parasympathetic actions that normally stimulate salivation and accommodation for near vision. When someone overdoses on atropine, these effects are pronounced, leading to dryness and blurred vision, along with tachycardia and reduced sweating. In the context of treating cardiac dysrhythmias, atropine is the drug that fits this overdose pattern. Other antiarrhythmics have different overdose presentations—lidocaine tends to cause CNS effects and conduction issues, adenosine can cause flushing and transient block symptoms, and amiodarone can produce hypotension and organ toxicity—rather than the characteristic anticholinergic signs.