Methanol Poisoning

 

Substance

-       Methanol

-       CH₃OH

 

Common name or Trade name

-       甲醇

-       Used in 抗凍劑, 溶劑, 皮革工廠, 染料塗料

 

Involving system [1]

-       Metabolic acidosis. lethargy

-       GI system:

-       Neurologic system: after poisoning 8 months to 2 years, secondary Parkinsonism.

-       Eye: Retinopathy, blindness.

 

 Presentation [1]

-       6—12 hours, 18—24 hours even 60 hours. After ingestion.

-       Blurred vision.

-       Stupor, coma.

-       Headache

-       SOB

-       Nausea. Abdomen pain, diarrhea.

-       High anion gap acidosis.

-       High osmolar gap acidosis

 

Antidote and Treatment [2]

-       Decontamination.

-       Carbomix (activated charcoal) is useless.

-       Intubation while acute respiratory failure.

-       ACLS

-       Ethanol: competition of aldehyde dehydrogenase, 1 gm/kg BW= 紹興(18%) 6ml/ kg BW till seral ethanol level 100—150 mg/dl. [1]

-       Fomepizole: 10—20 mg/kg / day * 3—5 days. (inhibit metabolism of methanol). [1]

-       Hemodialysis. [1]

-       Folic acid: 50 mg IV every 4 - 6 hours until toxicity resolves (increase formic acid oxidation into carbon dioxide and water). [3]. https://www.ebmconsult.com/articles/methanol-toxicology

-       Leucovorin dose: 1 mg/kg (50-70 mg adults) IV q4-6hr. (Folinic acid or leucovorin, the biologically active forms of folic acid, must be used for reversing toxicity due to dihydrofolate reductase inhibitors.)

Disposition 

-       Admit to ICU if severe acidosis, SOB, respiratory failure, or acute kidney injury  

-       Consult ophthalmologist if there is symptoms of eye.

  

REFERENCES

[1]. 急診醫學會, AILS 三版 p.255—265

[2]. Barceloux DG, Bond GR, Krenzelok EP, Cooper H, Vale JA; American Academy of Clinical Toxicology Ad Hoc Committee on the Treatment Guidelines for Methanol Poisoning. American Academy of Clinical Toxicology practice guidelines on the treatment of methanol poisoning. J Toxicol Clin Toxicol. 2002;40(4):415-46. doi: 10.1081/clt-120006745. PMID: 12216995.

[3]. Lim CS, Bryant SM. Forgoing the Folate?-Contemporary Recommendations for Methanol Poisoning and Evidence Review. Am J Ther. 2016 May-Jun;23(3):e850-4. doi: 10.1097/MJT.0000000000000059. PMID: 24531405.

edited  by Yu-Jang Su          Nov 28, 2020