China
Africa
Explore chapters and articles related to this topic
Toxins in Neuro-Ophthalmology
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Methanol poisoning usually results from either accidental or suicidal ingestion of products containing methanol [14–17]. Cases are common in developing countries among poor socioeconomic classes. It is first metabolized by the enzyme alcohol dehydrogenase (ADH) in the liver, via formaldehyde to formic acid. The optic nerve toxicity develops from a combined effect of the metabolic acidosis and formate anion.
Miscellaneous poisons
Published in Jason Payne-James, Richard Jones, Simpson's Forensic Medicine, 2019
Jason Payne-James, Richard Jones
Methanol poisoning treatment can include administration of ethanol or fomepizole, both inhibitors of the enzyme alcohol dehydrogenase to prevent formation of its metabolites, and hemodialysis to remove methanol and formate. Supplemental treatment with sodium bicarbonate for metabolic acidosis and haemodialysis or even haemodiafiltration can be used to remove methanol and formate from the blood.
Interaction of Alcohol with Medications and Other Drugs
Published in John Brick, Handbook of the Medical Consequences of Alcohol and Drug Abuse, 2012
John Brick, Mark C. Wallen, William J. Lorman
Alcoholics may drink other forms of alcohol when beverage alcohol (ethanol) is not available. One such alcohol, methanol (methyl alcohol), is highly toxic and may result in metabolic acidosis, blindness, and death. The interaction between ethanol and methanol is critical in averting methanol poisoning. Methanol is metabolized by the enzyme ADH to formaldehyde and then to formic acid, a highly toxic compound. Even when relatively small doses of methanol (several ounces) are consumed, these metabolites may cause metabolic acidosis, blindness, and cardiovascular instability and death. It is noteworthy that methanol poisoning can be prevented by the administration of ethyl alcohol because ethanol (alcohol) is preferentially metabolized by ADH, thereby decreasing the formation of toxic metabolites. The decrease in methanol metabolism allows methanol to be excreted unchanged and before toxic metabolites are formed. Patients admitted for acute intoxication or detoxification should be screened for methanol use so that appropriate prophylactic treatment (e.g., hemodialysis, ADH inhibitors, and ethanol administration) can be initiated.
Intentional avermectin pesticide ingestion: a retrospective multicenter study
Published in Clinical Toxicology, 2022
Yi-Kan Wu, Chia-Hau Chang, Jiun-Hao Yu, Kai-Ping Lan, Tzung-Hai Yen, Shu-Sen Chang, Chen-June Seak, Hsing-Yuan Chang, Hsien-Yi Chen
Solvents and additives in pesticides can contribute to toxicity following ingestion, especially when the solvents contain methanol. In Taiwan, dozens of abamectin and emamectin pesticide products are commercially available, and the majority do not clearly disclose the solvent ingredients on the label. Based on previous case reports, the solvents in abamectin and emamectin pesticides may contain hexanol, antioxidant butylated hydroxytoluene, N-methylpyrrolidone, and paraffinic oil, which may contribute to the CNS, GI, and cardiovascular symptoms observed in avermectin pesticide poisoning [12,14]. Concurrent methanol poisoning via solvent was reported in a patient who ingested methomyl pesticide [35]. Despite the potential for severe toxicity, patients with concurrent methanol exposure did not have worse outcomes compared to those without methanol exposure in our study. This was probably due to commercial avermectin pesticides having low concentrations of methanol, or to the small number of methanol exposure cases in our study. Patients with methanol poisoning usually require specific therapy to prevent mortality and minimize complications. Clinicians should be aware of the possibility of concurrent methanol poisoning in patients who ingest liquid avermectin pesticides.
The effect of idebenone and corticosteroid treatment on methanol-induced toxic optic nerve and retinal damage in rats: biochemical and histopathological examination
Published in Cutaneous and Ocular Toxicology, 2022
Pinar Nalcacioglu, Sevim Kavuncu, Tugba Taskin Turkmenoglu, Cigdem Atay Sonmez
The visual loss following methanol intoxication may be temporary or permanent. It develops within 12 to 72 h after methanol ingestion and can be progressive, painless, severe, and bilateral. The treatment has three primary goals: treating metabolic acidosis, inhibiting the metabolism of methanol, and increasing the elimination of the unmetabolized compounds and toxic metabolites14. Some antidotes such as ethanol and fomepizole are used to prevent formic acid formation and metabolic acidosis when treating methanol poisoning. However, these antidotes cannot reverse vision loss once the visual symptoms begin1. In our experimental study, oral CoQ10 and IV steroids were administered at 4 h following methanol ingestion as indicated in other studies15,16 for therapeutic purposes in case of ON and retinal layer damage.
Health-related quality of life determinants in survivors of a mass methanol poisoning outbreak: six-year prospective cohort study
Published in Clinical Toxicology, 2020
Jan Rulisek, Petr Waldauf, Jan Belohlavek, Martin Balik, Katerina Kotikova, Jiri Hlusicka, Manuela Vaneckova, Zdenek Seidl, Pavel Diblik, Jan Bydzovsky, Jarmila Heissigerova, Pavel Urban, Michal Miovsky, Jaroslav Sejvl, Daniela Pelclova, Sergey Zakharov
Fomepizole and ethanol are two antidotes applied for the treatment of acute methanol poisoning; both block alcohol dehydrogenase and stop formic acid production. Fomepizole is the preferred antidote over ethanol because its pharmacokinetics are more predictable than ethanol, it has a safer side effect profile, it shortens intensive care unit (ICU) and hospital stays, and it can decrease the need for hemodialysis. In our previous study, we did not find any difference in outcome, length of ICU stay, or dialysis between patients treated with fomepizole or ethanol [41]. In the present study, there was no association between the types of antidote applied in the hospital with follow-up quality of life of survivors of methanol poisoning. Therefore, no antidote demonstrated an advantage from the perspective of long-term quality of life; both antidotes can be applied without concerns on grounds of effectiveness.