Leucovorin (calcium folinate) in “antifreeze” poisoning
Date First Published:
October 15, 2000
Last Updated:
September 5, 2003
Report by:
Angaj Ghosh, Senior Clinical Fellow in Emergency Medicine (Manchester Royal Infirmary)
Search checked by:
Russel Boyd, Manchester Royal Infirmary
Three-Part Question:
In [an adult with methanol/ethylene glycol poisoning] is [the addition of IV Calcium folinate better than ethanol alone] at [reducing the incidence of reduced acuity and retinal oedema)]?
Clinical Scenario:
A man attends the emergency department having deliberately taken 150 ml of "antifreeze". The can of antifreeze has conveniently been brought along and you find it consists of a mixture of methanol and ethylene glycol. The Poisons Centre is contacted. In addition to treatment with ethanol it is suggested that intravenous Leucovorin (calcium folinate) is given. You wonder if there is any evidence to support this recommendation.
Search Strategy:
Medline 1996-06/03 using the OVID interface.
Search Details:
[exp leucovorin OR folinic acid.mp OR Calcium folinate.mp] AND [exp methanol OR methanol.mp OR exp ethylene glycol OR ethylene glycol.mp OR antifreeze.mp] LIMIT to English.
Outcome:
Altogether 12 papers were found, none of which were relevant to humans. One paper published in two different journals described studies on monkeys and suggested that the results could be extrapolated to humans.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| The role of folates in methanol toxicity. Noker PE, Tephly TR. 1980, USA | Cynomolgus monkeys Effects of 5-fTHF or sodium folate following methanol poisoning are assessed |
Experimental study | Metabolic acidosis | Did not develop in treated monkeys | |
| Serum formate level | Lower than untreated monkeys: (p<0.05) |
Author Commentary:
In humans methanol toxicity is characterised by a metabolic acidosis and an ocular toxicity that occur coincident with an accumulation of formate in blood. After experimental studies on monkeys, Noker and Tephly hypothesised that folate compounds could decrease formate accumulation after methanol by stimulating formate oxidation or utilisation and suggested a possible use for folates in the treatment of certain cases of human methanol poisoning.
Bottom Line:
There is no direct evidence of the usefulness of folates in methanol poisoning in humans. Local policy should be followed.
Level of Evidence:
Level 3: Small numbers of small studies or great heterogeneity or very different population
References:
- Noker PE, Tephly TR.. The role of folates in methanol toxicity.