Fixed 12-h vs 20–21-h IV acetylcysteine in acetaminophen poisoning: RCT systematic review and meta-analysis

Fixed 12-h vs 20–21-h IV acetylcysteine in acetaminophen poisoning: RCT systematic review and meta-analysis | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL This is a preprint and has not been peer reviewed. Data may be preliminary. 27 February 2026 V1 Latest version Share on Fixed 12-h vs 20–21-h IV acetylcysteine in acetaminophen poisoning: RCT systematic review and meta-analysis Authors : Omid Mehrpour 0000-0002-1070-8841 [email protected] , Alireza Amirabadizadeh , and Farshad Shirazi M Authors Info & Affiliations https://doi.org/10.22541/au.177219370.07680980/v1 138 views 68 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract Aim: Intravenous N-acetylcysteine regimens for acetaminophen poisoning are increasingly simplified to reduce infusion reactions and early emesis while maintaining hepatic protection, but direct regimen-to-regimen randomized evidence comparing fixed 12-hour and fixed 20–21-hour regimens is limited. Methods: We searched MEDLINE, Embase and CENTRAL (to 10 Dec 2025) for individually randomized trials comparing fixed 12-hour versus fixed 20–21-hour intravenous N-acetylcysteine, with Cochrane Risk of Bias 2 (RoB 2) assessment. With only two heterogeneous trials, we report trial-specific effects. Results: Two trials were included (SNAP n=222; SARPO n=204). For trial-defined hypersensitivity/anaphylaxis-like reactions, SNAP favored 12 hours (risk ratio [RR] 0.72; 95% confidence interval [CI] 0.58–0.88) and SARPO was imprecise (RR 0.82; 95% CI 0.35–1.92). SNAP also reported less early vomiting/retching or rescue antiemetic use at 2 h (RR 0.55; 95% CI 0.42–0.74). SARPO met non-inferiority for ΔALT24 (margin 5 U/L), with a median difference of −1 U/L (95% CI −3 to 1) in low-risk early presenters. Conclusions: Across two regimen-to-regimen RCTs, the studied 12-hour packages reduced trial-defined reactions (clear benefit in SNAP; uncertainty in SARPO). Overall certainty is very low and hepatic efficacy remains uncertain, relying on ALT surrogates and underpowered for rare critical outcomes. Supplementary Material File (apap-metha updated word doc (2).docx) Download 343.67 KB Information & Authors Information Version history V1 Version 1 27 February 2026 Copyright This work is licensed under a Non Exclusive No Reuse License. Authors Affiliations Omid Mehrpour 0000-0002-1070-8841 [email protected] Medical Toxicology LLC View all articles by this author Alireza Amirabadizadeh Birjand University of Medical Sciences View all articles by this author Farshad Shirazi M Arizona Poison & Drug Information Center View all articles by this author Metrics & Citations Metrics Article Usage 138 views 68 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Omid Mehrpour, Alireza Amirabadizadeh, Farshad Shirazi M. Fixed 12-h vs 20–21-h IV acetylcysteine in acetaminophen poisoning: RCT systematic review and meta-analysis. 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