Clinical Characteristics and Prognostic Factors in Methanol Intoxication: A Retrospective Study from a Tertiary Emergency Department

Year 2025, Volume: 7 Issue: 2, 32 - 36, 31.08.2025

Mustafa Açıkgöz , Hakan Barış Demirbaş , Caner Sağlam , Erden Erol Ünlüer

https://doi.org/10.51262/ejtox.1755468

Abstract

Objective:
Methanol poisoning remains a major cause of toxicological mortality due to the diagnostic challenges and delayed presentation. This study aimed to evaluate the epidemiological profile, clinical features, laboratory parameters and outcomes of patients presenting to the emergency department with methanol intoxication.
Methods:
This retrospective study included patients admitted to our emergency department between January 1, 2017, and January 1, 2021, with a clinical diagnosis of methanol poisoning. Inclusion criteria were: suspected methanol ingestion, supportive history and physical findings, and high anion gap metabolic acidosis (pH < 7.3, HCO₃ < 20 mEq/L, anion gap > 20 mEq/L). Demographic data, presenting symptoms, laboratory values, and outcomes were compared between survivor and non-survivor groups.
Results:
Among 41 patients, 87.8% were male with a mean age of 52.2 ± 10.8 years. In-hospital mortality was 41.5%. Altered mental status at presentation was significantly more frequent in non-survivors (64.7%) than survivors (25.0%, p = 0.011). Mortality among patients with altered consciousness reached 69.2%. Survivors presented more often with visual complaints (54.2% vs. 23.5%), though the difference was not statistically significant(0.101). Non-survivors had lower mean pulse rates (84.5 ± 23.2 vs. 106.0 ± 26.6 bpm, p = 0.004), and more severe metabolic acidosis (mean pH 6.86 ± 0.23, HCO₃ 6.66 ± 3.57, base deficit −23.77 ± 5.23). ROC analysis confirmed strong associations between mortality and low pH, bicarbonate, and base deficit levels, as well as elevated lactate, glucose, and anion gap values.
Conclusion:
Methanol poisoning diagnosis is primarily clinical, and early detection is vital to reduce morbidity and mortality. The severity of metabolic acidosis and altered mental status at admission are key indicators of poor prognosis.

Keywords

Methanol poisoning , metabolic acidosis , antidotal therapy , emergency medicine , prognostic factors

Supporting Institution

None

References

• Wright J, et al. Methanol Toxicity. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024. (Updated 2025 Jan 1). Available from: https://www.ncbi.nlm.nih.gov/books/NBK482121/
• Nekoukar Z, Zakariaei Z, Taghizadeh F, Musavi F, Banimostafavi ES, Sharifpour A, et al. Methanol poisoning as a new world challenge: a review. Ann Med Surg (Lond). 2021 Jun 2;66:102445. doi:10.1016/j.amsu.2021.102445
• Tabatabaei SA, Amini M, Haydar AA, Soleimani M, Cheraqpour K, Shahriari M, et al. Outbreak of methanol-induced optic neuropathy in early COVID-19 era; effectiveness of erythropoietin and methylprednisolone therapy. World J Clin Cases. 2023;11(15):3502–3510. doi:10.12998/wjcc.v11.i15.3502.
• Alrashed M, Aldeghaither NS, Almutairi SY, Almutairi M, Alghamdi A, Alqahtani T, et al. The perils of methanol exposure: insights into toxicity and clinical management. Toxics. 2024;12(12):924. doi:10.3390/toxics12120924.
• Perkins JE, Hovda KE, Chowdhury FR, Brandt Sørensen J, Eddleston M, Street A. Alcohol as poison: a narrative review of social science scholarship relevant to methanol poisoning in low- and middle-income countries. Alcohol Alcohol. 2025;60(3):agaf018. doi:10.1093/alcalc/agaf018.
• Nafea OE, Abdelhamid WG, Ibrahim F. The role of the leukocyte glucose index in predicting clinical outcomes in acute methanol toxicity. Toxicol Rep. 2025;14:101994. doi:10.1016/j.toxrep.2025.101994. PMID: 40177603; PMCID: PMC11964667.
• Aghababaeian H, Araghi Ahvazi L, Ostadtaghizadeh A. The methanol poisoning outbreaks in Iran 2018. Alcohol Alcohol. 2019;54(2):128–130. doi:10.1093/alcalc/agz005. PMID: 30715164.
• Güler S, Üçöz Kocaşaban D. An outbreak of home‑distillation methanol poisoning in Turkey during the COVID‑19 pandemic: a single‑center experience. Arch Iran Med. 2024;27(3):151–158. doi:10.34172/aim.2024.23. PMID: 38685840; PMCID: PMC11097313.
• Alhusain F, Alshalhoub M, Bin Homaid M, Abu Esba LCA, Alghafees M, Al Deeb M. Clinical presentation and management of methanol poisoning outbreaks in Riyadh, Saudi Arabia: a retrospective analysis. BMC Emerg Med. 2024;24(1):64. doi:10.1186/s12873-024-00976-1. PMID: 38627622; PMCID: PMC11020920.
• Zakharov S, Pelclova D, Urban P, Navratil T, Diblik P, Kuthan P, et al. Czech mass methanol outbreak 2012: epidemiology, challenges and clinical features. Clin Toxicol (Phila). 2014;52(10):1013–1024. doi:10.3109/15563650.2014.974106. PMID: 25314075.
• Hassanian-Moghaddam, H., Zamani, N., Kolahi, A. A., McDonald, R., & Hovda, K. E. (2020). Double trouble: methanol outbreak in the wake of the COVID-19 pandemic in Iran-a cross-sectional assessment. Critical care (London, England), 24(1), 402. https://doi.org/10.1186/s13054-020-03140-w
• Simani L, Ramezani M, Roozbeh M, Shadnia S, Pakdaman H. The outbreak of methanol intoxication during COVID-19 pandemic: prevalence of brain lesions and its predisposing factors. Drug Chem Toxicol. 2022;45(4):1500–1503. doi:10.1080/01480545.2020.1845192.
• Md Noor J, Hawari R, Mokhtar MF, Yussof SJ, Chew N, Norzan NA, et al. Methanol outbreak: a Malaysian tertiary hospital experience. Int J Emerg Med. 2020;13(1):6. doi:10.1186/s12245-020-0264-5.
• Essayagh S, Bahalou M, Essayagh M, Essayagh T. Epidemiological profile of methanol poisoning, El Hajeb, Morocco. East Mediterr Health J. 2020;26(11):1425–1429. doi:10.26719/2020.26.11.1425.
• Kumar M, Kaeley N, Nagasubramanyam V, Bhardwaj BB, Kumar S, Kabi A, et al. Single center experience of managing methanol poisoning in the hilly state of Uttarakhand: a cross-sectional study. Int J Crit Illn Inj Sci. 2019;9(4):172–176. doi:10.4103/IJCIIS.IJCIIS_49_19. Kaewput W, Thongprayoon C, Petnak T, Chewcharat A, Boonpheng B, Bathini T, et al. Inpatient burden and mortality of methanol intoxication in the United States. Am J Med Sci. 2021;361(1):69–74. doi:10.1016/j.amjms.2020.08.014.
• Yousefinejad V, Moradi B, Mohammadi Baneh A, Sheikhesmaeili F, Babahajian A. Prognostic factors of outcome in methanol poisoning: an 8-year retrospective cross-sectional study. Arch Acad Emerg Med. 2020;8(1):e69.
• Gulen M, Satar S, Avci A, Acehan S, Orhan U, Nazik H. Methanol poisoning in Turkey: two outbreaks, a single center experience. Alcohol. 2020;88:83–90. doi:10.1016/j.alcohol.2020.07.002.
• Abdelhamid WG, El-Sarnagawy GN, Sobh ZK. Outcome assessment of acute methanol poisoning: a risk-prediction nomogram approach for in-hospital mortality. Toxicol Rep. 2024;13:101817. doi:10.1016/j.toxrep.2024.101817.
• Sasani MR, Molavi Vardanjani H, Mehdipour Namdar Z, Jeddi M, Seif S, Sedighi S, et al. Prognosis of methanol poisoning in a developing setting. Arch Iran Med. 2024;27(3):127–134. doi:10.34172/aim.2024.20.
• Coskun A, Demirci B, Oymak I, Ferhatlar E, Eren SH. Electrocardiographic changes, mortality, and late period findings in methyl alcohol poisoning. J Clin Med. 2024;13(19):5999. doi:10.3390/jcm13195999.
• Yurtsever G, Arıkan C, Acar H, Sorgun O, Bora ES. Methanol poisoning in the emergency department: a retrospective study. J Health Sci Med / JHSM. July 2022;5(4):949-953. doi:10.32322/jhsm.1095045