At 2330, a client arrives in the emergency department after ingesting about 20 g of immediate-release acetaminophen at 2200. The client is alert, is protecting the airway, and has not vomited. The laboratory can report a serum acetaminophen level within 1 hour. Which prescription should the nurse implement now?
1Start IV acetylcysteine now, before any serum level is drawn
2Draw a serum acetaminophen level now to plot on the nomogram
3Give syrup of ipecac now to empty the stomach of any tablets
4Give oral activated charcoal now while the client is alert✓ Correct answer
Explanation
At 90 minutes after a known-time ingestion in an alert client with a protected airway, activated charcoal can still reduce absorption. The 4-hour level (0200) guides acetylcysteine, which is highly effective when started within 8 hours, so it does not need to be started blindly when the level will be available in time. A level drawn now, before 4 hours, cannot be plotted on the nomogram.
Why this is correct The timing details decide the order. The ingestion was 90 minutes ago, so charcoal can still bind drug in the gut, and the client is alert with a protected airway, so it is safe to give. The 4-hour level will be drawn at 0200 and resulted by 0300, well within the 8-hour window for acetylcysteine.
Easy analogy or mental picture Charcoal is a net you can only throw while the tablets are still in the stomach; acetylcysteine is the rescue team that can still arrive on time later.
Memory hook Known time + early + alert airway = CHARCOAL now, LEVEL at 4 hours, NAC by 8 hours.
NCLEX decision rule In poisoning questions, place each intervention on the timeline from ingestion and choose the one whose window is closing first.
Why the other choices are wrong Starting acetylcysteine immediately is correct when the ingestion time is unknown or a level cannot be resulted before 8 hours, which is why it tempts, but here the level will be back in time. Drawing a level now is the right test at the wrong time: levels before 4 hours are uninterpretable on the Rumack-Matthew nomogram. Syrup of ipecac is still found in older teaching and home cabinets but is no longer recommended because vomiting delays charcoal and adds aspiration risk.
References
1Dart RC et al. Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement (JAMA Netw Open 2023)Activated charcoal for recent ingestion; 4-hour level plotted on the nomogram; start acetylcysteine if the level will not be available within 8 hours
2StatPearls: Acetaminophen ToxicityLevels drawn before 4 hours cannot be interpreted on the Rumack-Matthew nomogram
ScenarioAn alert client arrives 90 minutes after a known-time ingestion of 20 g of acetaminophen.
Activated charcoal — An adsorbent that binds drugs still in the gut when given soon after ingestion.
Rumack-Matthew nomogram — A graph that uses a level drawn 4 or more hours after ingestion to predict hepatotoxicity risk.
Acetylcysteine (NAC) — The antidote that replenishes glutathione and is most effective within 8 hours of ingestion.