E-DRUG: IV Ethanol or fomepizole for methanol poisoning? (2)
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Dear Ozma Fazal,
Here is a protocol for treating methanol poisoning from a manual for
drug therapy in emergency medicine that I authored a few years ago.
I'm pasting in the material since e drug can't accept attachments so I
apologize if there is trouble reading the material.
Joel Lexchin
121 Walmer Rd.
Toronto, ON
Canada
e mail: joel.lexchin@utoronto.ca
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Ethylene glycol and methanol poisoning
Drugs of choice1?3
1. For both methanol and ethylene glycol poisoning
ethanol 10% solution loading dose of 0.6?0.7 g/kg, I.V.
bolus (7.6 mL of solution/kg); then
maintenance dose of 66?308 mg/kg
(0.8?4.0 mL/kg) per h to maintain
ethanol level of 22?33 mmol/L
or fomepizole 15 mg/kg, I.V.; then
10 mg/kg, I.V., q12h (1 g/mL)
AND, in addition to either of the above, to treat metabolic acidosis
sodium bicarbonate (50 mmol in 50-mL ampoule)
Adults up to 400?600 mmol, I.V.
in the first few hours
Children 8?12 mmol/kg, I.V. in
first few hours
2. For ethylene glycol poisoning, add
thiamine 100 mg, I.M. or I.V., q6h
AND
pyridoxine 50 mg, I.M. or I.V., q6h
3. For methanol poisoning, add
folic acid 50 mg, I.V., q4h ( 6 doses
Additional instructions and notes
* Treatment with either fomepizole or ethanol should be started as
soon as possible to prevent the metabolism of ethylene glycol and
methanol.
* Fomepizole does not replace hemodialysis in the management of
methanol poisoning and most ethylene glycol poisonings because of the
effect of alcohol dehydrogenase blockade on the elimination kinetics
of both methanol and ethylene glycol.
* More frequent dosing with fomepizole is required in patients
undergoing dialysis, as fomepizole is removed during that procedure.
* The routine administration of calcium to correct hypocalcemia in
ethylene glycol poisoning is not recommended because of the potential
to increase the formation of calcium oxalate crystals.3
References
1. Brent J, McMartin K, Phillips S, Burkhart KK, Donovan JW, Wells M, et al. Fomepizole for the treatment of ethylene glycol poisoning. N
Engl J Med 1999;340:832-8.
2. Brent J, McMartin K, Phillips S, Aaron C, Kulig K. Fomepizole for
the treatment of methanol poisoning. N Engl J Med 2000;344:424-9.
3. Barceloux DG, Krenzelok EP, Olson K, Watson W. American Academy of Clinical Toxicology practice guidelines on the treatment of ethylene
glycol poisoning. Clin Toxicol 1999;37:537-60.