FPGEE for National Association of Boards of Pharmacy (NABP) Practice Exam

Which medication is used to reverse AChE inhibitor poisoning?

1. Atropine

2. Pralidoxime

3. Calcium chloride

4. Sodium nitrite

The correct answer is: Pralidoxime

The medication used to reverse acetylcholinesterase (AChE) inhibitor poisoning is pralidoxime. AChE inhibitors, such as certain pesticides and nerve agents, work by preventing the breakdown of acetylcholine in the body, leading to an accumulation of this neurotransmitter and resulting in overstimulation of acetylcholine receptors. This can cause severe symptoms including muscle paralysis and respiratory failure. Pralidoxime acts by reactivating the inhibited acetylcholinesterase enzyme, thereby restoring its function and allowing for the degradation of excess acetylcholine. By doing so, pralidoxime helps alleviate the toxic effects of the AChE inhibitors, particularly if administered soon after exposure. In contrast, atropine is often used to treat the symptoms of AChE inhibitor poisoning by blocking acetylcholine receptors, which can provide symptomatic relief but does not address the underlying problem of the inhibited enzyme. Calcium chloride is used in conditions like hypocalcemia and does not have a role in AChE inhibitor poisoning. Sodium nitrite is primarily used in cases of cyanide poisoning and does not have any relevance in the context of AChE inhibitors. Thus, the specific mechanism of action of pralidoxime makes it the appropriate choice for