Formic acid alcohol ingestion

The kinetic parameters for the oxidation of a series of alcohols by ALD are shown in Table 4.1 (74). Methanol and ethylene glycol are toxic because of their oxidation products (formaldehyde and formic acid for methanol and a series of intermediates leading to oxalic acid for ethylene glycol), and the fact that their affinity for ALD is lower than that for ethanol can be used for the treatment of ingestion of these agents. Treatment of such patients with ethanol inhibits the oxidation of methanol and ethylene glycol (competitive inhibition) and shifts more of the clearance to renal clearance thus decreasing toxicity. ALD is also inhibited by 4-methylpyrazole. 

Methanol or methyl alcohol can become an alcoholic s main source of alcohol because it is cheaper. Methanol is frequently used as an additive for industrial ethanol to circumvent taxes. Methanol may be purposely adulterated to make it less palatable, but it is used nevertheless Methanol ingestion can be fatal due to its CNS depressant effects. In addition it is toxic because it is a substrate for alcohol dehydrogenase forming formic acid and formaldehyde which... 

Methyl alcohol is poisonous and is commonly used to denature ethyl alcohol. Methanol poisoning results from ingestion, inhalation of methanol vapors, or absorption through the skin. Methanol is transformed in the body to formaldehyde (H2CO) by the enzyme alcohol dehydrogenase. The formaldehyde is then metabolized to formic acid (HCOOH)... 

SAFETY PROFILE Moderately toxic by ingestion. Mildly toxic by inhalation. Human systemic effects by inhalation muscle contractions and spasticity, conjunctiva irritation, and unspecified respiratory changes. An irritant and narcotic in high concentrations. See also ESTERS, n-BUTYL ALCOHOL, and FORMIC ACID. Dangerous fire hazard when exposed to heat or flame. To fight fire, use alcohol foam, foam, CO2, dry chemical. Incompatible with oxidizing materials. When heated to decomposition it emits acrid and irritating fumes. 

Methyl alcohol is readily absorbed from the gastrointestinal tract, but is very slowly oxidized by the tissues. Approximately 30 percent of the absorbed alcohol remains unoxidized in the tissues 48 hours after ingestion. Roughly 40 percent of the compound is oxidized to formaldehyde and formic acid and a considerable quantity escapes in the exhaled air unchanged. Much of the formic acid formed is excreted in the urine as its sodium and ammonium salts. In addition to the depressant action of methyl alcohol upon the central nervous system, characteristic of the aliphatic alcohols, the compound elicits a definite toxic specificity for the optic nerve. 

Methanol is used as antifreeze and is also added to ethanol as a denatu-rant. Similarly, ethylene glycol is used as an antifreeze, especially in automobiles. Both compounds themselves are not toxic, but following ingestion they are metabolised rapidly by alcohol dehydrogenase to metabolites (formic acid and oxalic acid) which are potentially lethal. Fomepizole (4-methylp5Tazone) inhibits alcohol dehydrogenase and is used clinically to treat methanol and ethylene glycol toxicity. 

The metabolite produced from a drug or some other exogenous substance is often pharmacologically active. Such substances are referred to as active metabolites. In some cases, active metabolites are responsible for toxic effects which exceed that of the parent substance. Methanol, ethylene glycol, and DDE are examples of active toxic metabolites. Methanol (wood alcohol) can be ingested accidentally or intentionally. Methanol is metabolized similarly to ethanol, via a two-step oxidation to an aldehyde (formaldehyde) that is converted to an add (formic add). The acid causes toxic effects such as acidosis and Impaired cell respiration, while the penetration of methanol into the vitreous humor can lead to blurred vision emd blindness. 

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