Pediatric Acetaminophen Toxicity Medication

N -acetylcysteine (NAC), antiemetics, and activated charcoal are helpful in the treatment of acetaminophen toxicity. The American College of Emergency Physicians (ACEP) issued guidelines for acetaminophen overdose.^{[9, 10]}

Class Summary

N -acetylcysteine (NAC), a glutathione precursor, is the antidote of choice to prevent and treat acetaminophen-induced hepatotoxicity. This agent is indicated for all ingestions above the possible toxicity line on the Rumack-Matthew nomogram. The US Food and Drug Administration (FDA) approved both oral (PO) (Mucomyst) and intravenous (IV) (Acetadote) formulations. Three treatment protocols are recognized: 72-hour oral, 21-hour intravenous, and 48-hour intravenous. For maximum hepatoprotective effect, the antidote should be given within 8-10 hours of the acetaminophen ingestion.

N-acetylcysteine (Acetadote)

Oral (PO) antidote is available as a 20% solution (200 mg/mL). This should be diluted to 5% solution (50 mg/mL) with fruit juice or carbonated beverage. Aggressive antiemetic therapy is indicated in patients with nausea or vomiting due to acetaminophen-induced hepatic injury or foul smell of the solution. If the patient vomits within 60 min of administration, repeat the dose.

The intravenous (IV) formulation (Acetadote) is diluted in 5% dextrose in water (D5W) and infused according to the protocol for acute (within 8-10 h) or late-presenting or chronic acetaminophen ingestion.

The entire NAC protocol, either PO or IV regimen, should be completed even if the acetaminophen plasma levels decrease below the toxic range on the Rumack-Matthew nomogram.

Class Summary

Nausea and vomiting in acetaminophen-induced hepatotoxicity may due to acetaminophen, activated charcoal, or oral N -acetylcysteine (NAC). Antiemetic therapy is indicated in patients with these symptoms to enable successful treatment with oral NAC.

Metoclopramide (Reglan, Metozolv)

The antiemetic effect of metoclopramide appears to be due to its ability to block dopamine receptors in the chemoreceptor trigger zone (CTZ) of the central nervous system (CNS). This agent also enhances gastrointestinal motility and accelerates gastric emptying time.

Ondansetron (Zofran, Zuplenz)

Ondansetron is a selective 5-hydroxytryptamine (5HT3) receptor antagonist. This drug blocks serotonin by acting on the vagus nerve peripherally and at the chemoreceptor trigger zone (CTZ) of the central nervous system (CNS). Ondansetron is considered more effective than metoclopramide, with fewer adverse effects, but this agent tends to be more expensive than metoclopramide.

Class Summary

Consider decontamination with activated charcoal in any patient who presents within 4 hours after the ingestion. Activated charcoal may be helpful more than 4 hours postingestion if co-ingestion with an agent that slows gut motility occurred or if a sustained-release preparation was ingested.

Activated charcoal adsorbs acetaminophen, but its use has been controversial, because activated charcoal may absorb oral N -acetylcysteine (NAC). Although activated charcoal reduces the bioavailability of NAC, the small decrease in the NAC bioavailability is unlikely to reduce the effectiveness of oral NAC as an antidote.

Activated charcoal (Actidose-Aqua, EZ-Char, CharcoCaps, Charcoal Plus)

Activated charcoal is used for emergency treatment in poisoning caused by drugs and chemicals. A network of pores absorbs 100-1000 mg of drug per gram of charcoal. Activated charcoal prevents absorption by adsorbing the drug in the intestine; multidose charcoal may interrupt enterohepatic recirculation and enhance elimination by enterocapillary exsorption. In theory, by constantly bathing the gastrointestinal (GI) tract with charcoal, the intestinal lumen serves as a dialysis membrane for reverse absorption of the drug from the intestinal villous capillary blood into the intestine. Activated charcoal does not dissolve in water.

For maximum effect, administer this agent within 30 minutes after ingestion or poison.