https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 Retrospective evaluation of repeated supratherapeutic ingestion (RSTI) of paracetamol https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47721 1000 U/L). Method: Retrospective review of paracetamol RSTI presentations to two toxicology services over a four-year period. Patients were included if they ingested >4 g per 24 h of paracetamol for a period >8 h, regardless of intent. Data collected included demographics, ingestion history, pathology results, treatments and outcomes. Results: 266 patients were identified with median ingested dose of 9 g per 24 h (IQR: 6–12 g) over a median of 2 days (IQR: 1–5 days). On presentation, paracetamol was detected in 192 (72%), with median concentration of 14 mg/L (IQR: 7–27 mg/L). Median ALT on admission in those developing hepatotoxicity was significantly higher, 1182 U/L (IQR: 598–4251 U/L), compared to 30 U/L (IQR: 18–59 U/L; p < .0001) in those who did not. All 17 who developed hepatotoxicity had an ALT ≥50 U/L on presentation. Five patients presenting with an ALT <50 U/L developed a peak ALT between 50 and 1000 U/L, of which three had a paracetamol concentration <20 mg/L. 139 (52%) received acetylcysteine, of which 64 received an abbreviated course (<20 h), with a median length of infusion of 11 h (IQR: 7–14 h). 127 (48%) patients were not treated with acetylcysteine, none of these patients returned to hospital. Conclusions: Our results confirm that those developing hepatotoxicity from RSTI of paracetamol have an elevated ALT on presentation. Presenting ALT <50 U/L appears to be a safe threshold not to administer acetylcysteine, provided the paracetamol concentration is low.]]> Wed 25 Jan 2023 13:37:11 AEDT ]]> Early acetaminophen-protein adducts predict hepatotoxicity following overdose (ATOM-5) https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:45649 1,000 U/L), an adduct concentration ≥1.0 nmol/ml is sensitive and specific for identifying cases secondary to acetaminophen. Our aim was to characterise acetaminophen-protein adduct concentrations in patients following acetaminophen overdose and determine if they predict toxicity. Methods: We performed a multicentre prospective observational study, recruiting patients 14 years of age or older with acetaminophen overdose regardless of intent or formulation. Three serum samples were obtained within the first 24 h of presentation and analysed for acetaminophen-protein adducts. Acetaminophen-protein adduct concentrations were compared to ALT and other indicators of toxicity. Results: Of the 240 patients who participated, 204 (85%) presented following acute ingestions, with a median ingested dose of 20 g (IQR 10–40), and 228 (95%) were treated with intravenous acetylcysteine at a median time of 6 h (IQR 3.5–10.5) post-ingestion. Thirty-six (15%) patients developed hepatotoxicity, of whom 22 had an ALT ≤1,000 U/L at the time of initial acetaminophen-protein adduct measurement. Those who developed hepatotoxicity had a higher initial acetaminophen-protein adduct concentration compared to those who did not, 1.63 nmol/ml (IQR 0.76–2.02, n = 22) vs. 0.26 nmol/ml (IQR 0.15–0.41; n = 204; p <0.0001), respectively. The AUROC for hepatotoxicity was 0.98 (95% CI 0.96–1.00; n = 226; p <0.0001) with acetaminophen-protein adduct concentration and 0.89 (95% CI 0.82–0.96; n = 219; p <0.0001) with ALT. An acetaminophen-protein adduct concentration of 0.58 nmol/ml was 100% sensitive and 91% specific for identifying patients with an initial ALT ≤1,000 U/L who would develop hepatotoxicity. Adding acetaminophen-protein adduct concentrations to risk prediction models improved prediction of hepatotoxicity to a level similar to that obtained by more complex models. Conclusion: Acetaminophen-protein adduct concentration on presentation predicted which patients with acetaminophen overdose subsequently developed hepatotoxicity, regardless of time of ingestion. An adduct threshold of 0.58 nmol/L was required for optimal prediction. Lay summary: Acetaminophen poisoning is one of the most common causes of liver injury. This study examined a new biomarker of acetaminophen toxicity, which measures the amount of toxic metabolite exposure called acetaminophen-protein adduct. We found that those who developed liver injury had a higher initial level of acetaminophen-protein adducts than those who did not. Clinical Trial registration: Australian Toxicology Monitoring (ATOM) Study–Australian Paracetamol Project: ACTRN12612001240831 (ANZCTR) Date of registration: 23/11/2012.]]> Thu 23 Mar 2023 13:56:06 AEDT ]]> Predicting the requirement for N-acetylcysteine in paracetamol poisoning from reported dose https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:14405 1000 U/L) and treatment (single dose-activated charcoal [SDAC] and NAC) were analysed. Data were analysed within a repeated measures logistic regression framework using NONMEM (ver 7.2). The primary outcome was administration of NAC, which was determined based on a serum paracetamol concentration greater than the nomogram line. Result.: There were 1571 admissions in 1303 patients, with a median age of 27 years (12–96 years) and 1140 (73%) were females. The median dose was 10 g (1–100 g). The paracetamol concentration was above the nomogram line in 337 of 1571 (22%) patients. Patients presenting later (first paracetamol concentration between 7 and 16 h post-overdose) compared to those presenting earlier (4–7 h post-overdose) were more likely to have hepatotoxicity (5.5% vs. 0.4%; p < 0.0001), have a toxic paracetamol concentration (34% vs. 18%; p  0.0001) and receive NAC (48% vs. 23%; p < 0.0001). SDAC reduced the probability of the paracetamol concentration being above the nomogram. Based on SDAC not being administered there was a 5% probability of requiring NAC at a dose of 6–9 g, a 10% chance of requiring NAC at a dose of 13–16 g, a 50% chance of requiring NAC at a dose of 30–34 g and a 90% chance for needing NAC at 48–50 g. Conclusion. Reported dose was a good predictor of a toxic paracetamol concentration and SDAC reduced the probability of the concentration being above the nomogram. These predictions may assist in determining which patients could be started on NAC immediately.]]> Sat 24 Mar 2018 08:24:53 AEDT ]]> Intravenous paracetamol toxicity in a malnourished child https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:14460 Sat 24 Mar 2018 08:19:18 AEDT ]]> The protective action of the aqueous extract of Auricularia polytricha in paracetamol induced hepatotoxicity in rats https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29637 Sat 24 Mar 2018 07:41:53 AEDT ]]> A prospective observational study of a novel 2-phase infusion protocol for the administration of acetylcysteine in paracetamol poisoning https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:23068 1000 U/L or abnormal ALT. Results: 654 paracetamol poisonings were treated with the new protocol; median age 29 y (15-98 y); 453 females; 576 acute and 78 staggered/chronic ingestions. In 420 (64%) acetylcysteine was stopped for low-risk paracetamol concentrations. An adverse reaction occurred in 229/654 admissions (35%; 95% CI: 31-39%): 173 (26.5%; 95% CI: 23-30%) only gastrointestinal, 50 (8%; 95% CI: 6-10%) skin only systemic hypersensitivity reactions; and three severe anaphylaxis (0.5%; 95% CI: 0.1-1.5%; all hypotension). Adverse reactions occurred in 111/231 (48%) receiving full treatment compared to 116/420 (28%) in whom the infusion was stopped early (absolute difference 20%; 95% CI: 13-28%; p < 0.0001). In 200 overdoses < 10 g, one had toxic paracetamol concentrations, but 53 developed reactions. Sixteen patients had an ALT > 1000 U/L and 24 an abnormal ALT attributable to paracetamol; all but one had treatment commenced >12 h post-ingestion. Conclusion: A 2-phase acetylcysteine infusion protocol results in a fewer reactions in patients with toxic paracetamol concentrations, but is not justified in patients with low-risk paracetamol concentrations.]]> Sat 24 Mar 2018 07:12:28 AEDT ]]> Enhanced oral bioavailability and hepatoprotective activity of thymoquinone in the form of phospholipidic nano-constructs https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46617 90%), controlled drug release pattern, and neutral surface charge (zeta potential of −0.65 mV). After oral administration of a single dose of PNC, it showed a relative bioavailability of 386.03% vis-à-vis plain TQ suspension. Further, TQ-loaded PNC demonstrated significant enhanced hepato-protective effect vis-à-vis pure TQ suspension and silymarin, as evidenced by reduction in the ALP, ALT, AST, bilirubin, and albumin level and ratified by histopathological analysis. Conclusion: TQ-loaded PNCs can be efficient nano-platforms for the management of hepatic disorders and promising drug delivery systems to enhance oral bioavailability of this hydrophobic molecule.]]> Mon 28 Nov 2022 10:50:56 AEDT ]]> Modified release paracetamol overdose: a prospective observational study (ATOM-3) https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:47473 14 years who ingested ≥10 g or 200 mg/kg (whichever is less) of MR paracetamol. Data collected included demographics, ingestion history, pathology results, treatments, and outcomes including hepatotoxicity (ALT >1000 U/L). Results: In total, 116 patients were recruited, 85(73%) were female. The median dose ingested was 32 g (IQR: 20–49 g) and median time to presentation was 3 h (IQR: 2–9 h). 78(67%) had an initial paracetamol concentration above the nomogram line (150 mg/L at 4 h). A further 12(10%) crossed the nomogram after repeat paracetamol measurements, of which five crossed after two non-toxic levels 4 h apart. Six had a double paracetamol peak, in three occurring >24 h post-ingestion. 113(97%) received acetylcysteine of which 67 received prolonged treatment beyond the standard 21 h. This was because of an elevated paracetamol concentration at the completion of acetylcysteine in 39 (median paracetamol concentration 25 mg/L, IQR: 16–62 mg/L). 21 (18%) developed hepatotoxicity, including six treated within 8 h of ingestion. Activated charcoal and double doses of acetylcysteine did not significantly decrease the risk of hepatotoxicity. Conclusions: Drug regulatory authorities are considering restrictions on MR paracetamol preparations. Following an acute MR paracetamol overdose, this study found that many patients had a persistently elevated paracetamol concentrations, many required prolonged treatment and some developed liver injury despite early acetylcysteine treatment. Furthermore, activated charcoal and increased acetylcysteine did not appear to significantly alter the risk of liver injury. Hence, research into better treatment strategies is required.]]> Mon 23 Jan 2023 11:05:44 AEDT ]]> Sulfate conjugation may be the key to hepatotoxicity in paracetamol overdose https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39807 Fri 24 Jun 2022 08:46:01 AEST ]]> Massive paracetamol overdose: an observational study of the effect of activated charcoal and increased acetylcysteine dose (ATOM-2) https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34253 1000 U/L). Results: Two hundred paracetamol overdoses were analysed, reported median dose ingested was 50 g (interquartile range (IQR): 45-60 g) and median paracetamol ratio 1.9 (IQR: 1.4-2.9, n = 173). One hundred and ninety-three received acetylcysteine at median time of 6.3 h (IQR: 4-9.3 h) post-ingestion. Twenty-eight (14%) developed hepatotoxicity, including six treated within 8 h of ingestion. Activated charcoal was administered to 49(25%), at median of 2 h post-ingestion (IQR:1.5-5 h). Those receiving activated charcoal (within 4 h of ingestion), had significantly lower paracetamol ratio versus those who did not: 1.4 (n = 33, IQR: 1.1-1.6) versus 2.2 (n = 140, IQR: 1.5-3.0) (p < .0001) (paracetamol concentration measured ≥ 1 h after charcoal). Furthermore, they had lower rates of hepatotoxicity [unadjusted OR: 0.12 (95% CI: < 0.001-0.91); adjusted for time to acetylcysteine OR: 0.20 (95%CI: 0.002-1.74)]. Seventy-nine had a paracetamol ratio ≥2, 43 received an increased dose of acetylcysteine in the first 21 h; most commonly a double dose in the last bag (100 to 200 mg/kg/16 h). Those receiving increased acetylcysteine had a significant decrease risk of hepatotoxicity [OR:0.27 (95% CI: 0.08-0.94)] . The OR remained similar after adjustment for time to acetylcysteine and paracetamol ratio. Conclusion: Massive paracetamol overdose can result in hepatotoxicity despite early treatment. Paracetamol concentrations were markedly reduced in those receiving activated charcoal within 4 h. In those with high paracetamol concentrations, treatment with increased acetylcysteine dose within 21 h was associated with a significant reduction in hepatotoxicity.]]> Fri 22 Feb 2019 16:55:23 AEDT ]]> Advances in the understanding of acetaminophen toxicity mechanisms: a clinical toxicology perspective https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:53167 Fri 17 Nov 2023 11:43:46 AEDT ]]>