https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 Acetaminophen Metabolites on Presentation Following an Acute Acetaminophen Overdose (ATOM-7) https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50481  1,000 U/L). The Australian Toxicology Monitoring (ATOM) study is a prospective observational study, recruiting via two poison information centers and four toxicology units. Patients following an acute APAP ingestion presenting < 24 hours post-ingestion were recruited. Initial samples were analyzed for APAP metabolites, those measured were the nontoxic glucuronide (APAP-Glu) and sulfate (APAP-Sul) conjugates and NAPQI (toxic metabolite) conjugates APAP-cysteine (APAP-Cys) and APAP-mercapturate (APAP-Mer). The primary outcome was hepatotoxicity. In this study, 200 patients were included, with a median ingested dose of 20 g, 191 received acetylcysteine at median time of 5.8 hours post-ingestion. Twenty-six patients developed hepatotoxicity, one had hepatotoxicity on arrival (excluded from analysis). Those who developed hepatotoxicity had significantly higher total CYP metabolite concentrations: (36.8 μmol/L interquartile range (IQR): 27.8-51.7 vs. 10.8 μmol/L IQR: 6.9-19.5) and these were a greater proportion of total metabolites (5.4%, IQR: 3.8-7.7) vs. 1.7%, IQR: 1.3-2.6, P < 0.001)]. Furthermore, those who developed hepatotoxicity had lower APAP-Sul concentrations (49.1 μmol/L, IQR: 24.7-72.2 vs. 78.7 μmol/L, IQR: 53.6-116.4) and lower percentage of APAP-Sul (6.3%, IQR: 4.6-10.9 vs. 13.1%, IQR, 9.1-20.8, P < 0.001)]. This study found that those who developed hepatotoxicity had higher APAP metabolites derived from CYP pathway and lower sulfation metabolite on presentation. APAP metabolites may be utilized in the future to identify patients who could benefit from increased acetylcysteine or newer adjunct or research therapies.]]> Wed 26 Jul 2023 18:22:28 AEST ]]> Retrospective evaluation of repeated supratherapeutic ingestion (RSTI) of paracetamol https://nova.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 ]]> 2-methyl-4-chlorophenoxyacetic acid (MCPA) and bromoxynil herbicide ingestion https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:33902 Wed 23 Jan 2019 10:40:16 AEDT ]]> A coagulopathic dilemma: snakes or genes https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:14541 Wed 11 Apr 2018 13:36:43 AEST ]]> Just ‘nanging’ around – harmful nitrous oxide use: a retrospective case series and review of Internet searches, social media posts and the coroner's database https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:50147 Wed 05 Jul 2023 13:57:15 AEST ]]> Population pharmacokinetics of immediate-release and modified-release paracetamol and its major metabolites in a supratherapeutic dosing study https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:45670 Wed 02 Nov 2022 16:06:29 AEDT ]]> Clinical outcomes from early use of digoxin-specific antibodies versus observation in chronic digoxin poisoning (ATOM-4) https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:46899 p = .06), systolic blood pressure of 110 mmHg (range: 65–180) vs 125 mmHg (range: 90–184) (p = .009), respectively. Digoxin concentrations 4.4 nmol/L (range: 3.3–9) vs 4.2 (range: 2–11.2) (p = .42) and potassium concentrations 5.4 mmol/L (range: 3–11) vs 5.1 mmol/L (range: 3.5–8.2) (p = .33) were similar. Median dose of digoxin-Fab used was 1.5 vials (IQR: 1–2). There were 9 (12%) deaths in the Fab group compared to 7 (14%) in those treated with supportive care (risk difference −2.5%; 95% CI: −14 to 9%; p = .68). The median LOS was six days in both groups. Mean changes in potassium concentration [−0.5 ± 0.1 vs. −0.4 ± 0.1 mmol/L; difference −0.1 (95% CI: −.02, 0.4), p = .70] and HR within 4 h [8 ± 1 vs. 7 ± 3 bpm; difference −1.0 (95% CI: −6.7, 4.8), p = 0.74] were similar in the two groups. Conclusions: This study did not appear to show any benefit from the routine use of digoxin-Fab in patients thought to have chronic digoxin poisoning. These patients have multiple co-morbidities that may be contributing to their clinical features, other treatments are often equally effective.are often equally effective.]]> Tue 06 Dec 2022 15:39:23 AEDT ]]> Angiotensin axis antagonists increase the incidence of haemodynamic instability in dihydropyridine calcium channel blocker poisoning https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:40438 14 years who took an overdose of dihydropyridines (amlodipine, felodipine, lercanidipine, nifedipine) were included. Concurrent overdoses with non-dihydropyridine CCBs, alpha-blockers and beta-blockers were excluded. Patient demographics, drugs exposure details, serial vital signs, treatments and outcome were collected. Results: There were 100 patients. 68 took mixed overdoses of dihydropyridines with ARBs/ACEIs and 32 took single overdoses of dihydropyridines without ARBs/ACEIs. The mixed group had lower median nadir mean arterial pressures (62 vs 75 mmHg, p < 0.001), more frequently had hypotension (OR 4.5, 95%CI: 1.7–11.9) or bradycardia (OR 8.8, 95%CI: 1.1–70). Multivariable analysis indicated the mixed overdoses had an 11.5 mmHg (95%CI: 4.9–18.1) lower minimum systolic blood pressure (SBP) compared with the single group; other factors associated with a lower minimum SBP were higher doses [2.3 mmHg (95%CI: 1.1–3.5) lower per 10 defined daily doses] and younger age [2.2 mmHg (95%CI: 0.3–4.2) higher per decade]. A larger proportion of the mixed ingestion group received intravenous fluids (OR 5.7, 95%CI: 1.8–18.6) and antidotes and/or vasopressors (OR 2.9, 95%CI: 1.004–8.6). Conclusion: Combined overdoses of dihydropyridines with ARBs/ACEIs caused more significant hypotension and required more haemodynamic support than overdoses of dihydropyridines alone.]]> Tue 02 Aug 2022 11:11:57 AEST ]]> Early acetaminophen-protein adducts predict hepatotoxicity following overdose (ATOM-5) https://nova.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 ]]> Evidence for the changing regimens of acetylcysteine https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:26190 Sat 24 Mar 2018 07:24:09 AEDT ]]> Modified release paracetamol overdose: a prospective observational study (ATOM-3) https://nova.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 ]]> N-acetylcysteine in the poisoned patient https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:44567 N-acetyl-p-benzoquinone imine in hepatocytes and enhances non-toxic sulphate conjugation. As NAC is the cornerstone of treatment in paracetamol poisoning, trials have mainly focused around optimising dose, duration, rate and route of administration, with the primary aim to decrease rates of adverse events, shorten treatment time and maintain efficacy. NAC use is not just confined to paracetamol and has been utilised for a wide variety of toxins and ingestions. These toxins range from herbicides, mushrooms, hydrocarbons and metals. NAC’s proposed mechanism of action for these toxins is as an antioxidant and/or glutathione replenishing. The evidence for its use in most other toxins is limited to animal studies, case reports and small case series, due to the uncommon occurrence of these toxin exposures. With these toxins NAC is often given in combination with other therapies, making it difficult to determine its utility for many toxins. Because of the relative safety of NAC and the high morbidity associated with many of these ingestions, NAC is often recommended.]]> Mon 17 Oct 2022 11:23:24 AEDT ]]> Sulfate conjugation may be the key to hepatotoxicity in paracetamol overdose https://nova.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://nova.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://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:53167 Fri 17 Nov 2023 11:43:46 AEDT ]]>