How to Recognize and Counteract Chemical Toxicity – Part 2

Chemists must make use of science with safety and conscience.


Chemistry should be part of history to unfold the mystery of molecules being wary.

Methanol poisoning, which may be accidental or as part of an attempted suicide, most commonly occurs following the drinking of tainted alcoholic beverages made with windshield washer fluid, and may rarely occur through extensive skin exposure or breathing in fumes.

Ethylene glycol poisoning may also be accidental (viz., from antifreeze) or as part of an attempted suicide. Ethylene glycol is more toxic than other diols.

Diethylene glycol (DEG) is a widely used solvent. It can be a normal ingredient in various consumer products, or a contaminant. DEG has also been misused to sweeten wine and beer, and to viscosity oral and topical pharmaceutical products. Its use has resulted in many epidemics of poisoning since the early 20th century. The allowed limit in medications like cough syrups in India and by the WHO (world health organization) is 0.1%.

An antidote can counteract a form of poisoning.



Click/tap to enlarge the image

ADH = Alcohol dehydrogenase, ALDH = Aldehyde dehydrogenase. Ox = Oxidation, CNS = Central nervous system, HEAA = 2-Hydroxyethoxyacetic acid, cB = Conjugate base

Fomepizole is an intravenously injectable medication for Methanol or Ethylene glycol poisoning and on the WHO’s list of essential medicines.

Other treatments for Ethylene glycol poisoning may include Sodium bicarbonate, Thiamine, and Magnesium.

As Fomepizole prolongs the half-life of Ethanol via inhibiting its metabolism to Acetaldehyde by ADH, its concurrent use with Ethanol is contraindicated.

The International Agency for Research on Cancer (IARC) has listed Acetaldehyde as a Group 1 human carcinogen. Acetaldehyde is "one of the most frequently found air toxins with cancer risk greater than one in a million."

Disulfiram is a medication used to treat chronic alcoholism by producing an acute sensitivity to Ethanol (as a beverage) and used as a second-line treatment, behind Acamprosate and Naltrexone, for alcohol dependence. Disulfiram does not reduce alcohol cravings; so, a major problem associated with this drug is extremely poor compliance.

Acamprosate is a medication which reduces cravings in alcoholism possibly by stabilizing chemical signalling in the brain that would otherwise be disrupted by alcohol withdrawal, and on the WHO's list of essential medicines. Acamprosate is not metabolized by the human body.

Naltrexone is primarily used to manage alcohol (or opioid) use disorder by reducing cravings and feelings of euphoria associated with substance use disorder, and on the WHO's list of essential medicines. Naltrexone is an opioid antagonist and works by blocking the effects of opioids, including both opioid drugs as well as opioids naturally produced in the brain. It is taken orally or by intramuscular injection.

Acamprosate may work better than Naltrexone for eliminating alcohol abuse, while Naltrexone may decrease the desire for alcohol to a greater extent. It is taken orally.

NOTE: Post updated since published

Astounding antidotes❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com❗

References:

(1)    Graham, T. W.; Fryhle, C. B.; Snyder, S. A. Organic Chemistry.; Hoboken, Nj John Wiley Et Sons, Inc, 2016.

(2)    Brown, C.; Ford, M. Higher Level Chemistry, 2nd ed.; Pearson Education: Harlow, Essex, 2014.

(3)    Wikipedia Contributors. Methanol toxicity. Wikipedia. https://en.wikipedia.org/wiki/Methanol_toxicity.

(4)    Ethylene glycol poisoning. Wikipedia. https://en.wikipedia.org/wiki/Ethylene_glycol_poisoning.

(5)    Diethylene glycol. Wikipedia. https://en.wikipedia.org/wiki/Diethylene_glycol.

(6)    Wikipedia Contributors. Fomepizole. Wikipedia.

(7)    Wikipedia Contributors. Acetaldehyde. Wikipedia. https://en.wikipedia.org/wiki/Acetaldehyde.‌

(8)    Disulfiram. Wikipedia. https://en.wikipedia.org/wiki/Disulfiram.

(9)    Acamprosate. Wikipedia. https://en.wikipedia.org/wiki/Acamprosate.

‌(10)    Wikipedia Contributors. Naltrexone. Wikipedia. https://en.wikipedia.org/wiki/Naltrexone.

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