Methanol is a colorless and flammable liquid produced through the distillation of decomposed wood particles (Noor et al., 2020). It's commonly used in a variety of products such as windshield washer fluid, antifreeze, perfumes, and fuel (Kraut, and Mullins, 2018). Methanol poisoning (MP) typically results from ingestion, but can also occur from inhalation or skin absorption. Methanol is not inherently toxic, but its metabolite, formic acid, is toxic and has a half-life of about 12 hours (Ghannoum et al., 2014, Roberts et al., 2015, Hovda et al., 2006). The slow rate of formic acid metabolism leads to a delay in the onset of clinical and laboratory symptoms, which typically appear 6 to 24 hours after exposure (Kraut and Mullins, 2018).

Acute MP can cause mild symptoms such as headache, altered mental status, blurred vision, abdominal pain, and vomiting. In severe cases, patients may experience blindness, severe metabolic acidosis, coma, and even death (Barceloux et al., 2002). Because methanol serum concentration (MSC) testing is not widely accessible, anion gap and serum osmolality gap are used to diagnose intoxication (Kraut, 2016). Treatment for MP often involves dialysis and the administration of ethanol or fomepizole. Despite progress in diagnosis and treatment, the death rate among patients remains high (Mégarbane et al., 2005). Delayed or insufficient treatment can result in a death rate of up to 40%, and even patients who survive may experience permanent blindness and long-term effects on their central nervous system (Bezdicek et al., 2017). Therefore, researchers are interested in preventive treatments for these complications. Studies have shown that systemic corticosteroids can prevent and treat vision complications in these patients (Abrishami et al., 2011, Kowalski et al., 2019, Shukla et al., 2006).

MP resulting from both illicit and domestic alcohol consumption is a significant global medical concern, as demonstrated by prior studies (Hovda et al., 2005, Paasma et al., 2007). Unfortunately, confusion surrounding the alleged protective and therapeutic benefits of alcohol use against COVID-19 has led to a public health crisis in Iran. This dangerous misconception has led to an increase in the consumption of household alcohol, which is often contaminated with methanol. The prevalence of MP has increased as a result, compounded by the prohibition of alcoholic beverages in Iran (Zamani et al., 2019). Despite the World Health Organization's (WHO) announcement that methanol use in hand sanitizer solutions is prohibited (WHO, 2006), cases of MP resulting from the ingestion of disinfectant solutions have been reported in various countries (Chan and Chan, 2018, Chan et al., 2017, Mowry et al., 2015, Rafizadeh et al., 2023). The COVID-19 pandemic outbreak in December 2019 (Guan et al., 2020) and the increased use of these solutions have led to a rise in poisoning cases during this period.

Diagnosing MP can be challenging, as decreased consciousness may be the initial symptom, hindering the patient's ability to provide a comprehensive medical history. Additionally, fear of legal consequences may delay seeking medical attention, potentially increasing mortality rates. Delayed presentation and symptom onset highlight the importance of prompt diagnosis and intervention to reduce mortality and minimize neurological complications. Researchers worldwide are actively seeking strategies to expedite diagnosis and identify affected patients. This study aims to investigate the clinical-epidemiological, diagnostic, and therapeutic aspects of MP in patients referred to two training hospitals in Mazandaran province, northern Iran, from 2016 to 2021. By analyzing clinical symptoms and diagnosis, we aim to enhance understanding of MP. Additionally, by evaluating the efficacy of various treatments in preventing complications or death, our findings may inform future studies on treatment strategies.