We received a comment about the use of activated charcoal in acetaminophen. Generally, we recommend considering activated charcoal only within the first hour of poisoning. There is some debate whether activated charcoal is beneficial beyond one hour if there are coingestants that may decrease GI motility eg, opioids, antimuscarinics. Tylenol PM (acetaminophen and diphenhydramine) is an example. There are concerns with giving activated charcoal to these patients as eg, diphenhydramine can cause somnolence, altered mental status, seizures, and increase the risk of aspiration of activated charcoal. Many toxicologists and poison centers have different practice patterns regarding activated charcoal. Regarding assessing for hepatotoxicity. The INR is usually the first laboratory to be elevated if significant toxicity followed by a transaminitis. If the patient presents with an unknown time of ingestion or chronic ingestion immediately start treatment with N-acetylcysteine while acetaminophen level and comprehensive metabolic panel are pending. In these cases, we are not plotting the acetaminophen on the nomogram, only looking if there is any measurable acetaminophen as this would be one of the indications for continuing N-acetylcysteine. Thanks! Sean
Of course the blood level/ nomogram use are key for acute ingestion decision making, and I really like the 150-150, but there is an additional 150 that I was taught (actually was 140 before we had iv NAC) . 150 mg/kg or more is a good ballpark acute ingestion dose (about 10 gms, as mentioned, in a 70kg person) that can be used to inform your worry quotient for toxicity risk, early, before your levels are back. Patient history/reliability may not lend itself to this estimation, and must consider variability of absorption etc, but might be useful in pedi ingestion where you may have a reliable adult reporter of dose taken or in that wonderful patient who gives you accurate info. Thanks for excellent summary. Steve H
Matia M. - June 22, 2022 2:46 PM
We received a comment about the use of activated charcoal in acetaminophen. Generally, we recommend considering activated charcoal only within the first hour of poisoning. There is some debate whether activated charcoal is beneficial beyond one hour if there are coingestants that may decrease GI motility eg, opioids, antimuscarinics. Tylenol PM (acetaminophen and diphenhydramine) is an example. There are concerns with giving activated charcoal to these patients as eg, diphenhydramine can cause somnolence, altered mental status, seizures, and increase the risk of aspiration of activated charcoal. Many toxicologists and poison centers have different practice patterns regarding activated charcoal.
Regarding assessing for hepatotoxicity. The INR is usually the first laboratory to be elevated if significant toxicity followed by a transaminitis.
If the patient presents with an unknown time of ingestion or chronic ingestion immediately start treatment with N-acetylcysteine while acetaminophen level and comprehensive metabolic panel are pending. In these cases, we are not plotting the acetaminophen on the nomogram, only looking if there is any measurable acetaminophen as this would be one of the indications for continuing N-acetylcysteine.
Thanks!
Sean
Stephen H. - June 23, 2022 3:11 PM
Of course the blood level/ nomogram use are key for acute ingestion decision making, and I really like the 150-150, but there is an additional 150 that I was taught (actually was 140 before we had iv NAC) . 150 mg/kg or more is a good ballpark acute ingestion dose (about 10 gms, as mentioned, in a 70kg person) that can be used to inform your worry quotient for toxicity risk, early, before your levels are back. Patient history/reliability may not lend itself to this estimation, and must consider variability of absorption etc, but might be useful in pedi ingestion where you may have a reliable adult reporter of dose taken or in that wonderful patient who gives you accurate info. Thanks for excellent summary. Steve H
Jessie W. - June 24, 2022 2:16 PM
Thank you, Steve!
Jessie