Toxic Syndromes: Ethylene Glycol & Methanol

ETHYLENE GLYCOL & METHANOL

Ethylene glycol and methanol are alcohols that are important toxins because of their metabolism to highly toxic organic acids . They are capable of causing CNS depression and a drunken state similar to ethanol overdose. In addition, their products of metabolism—formic acid (from methanol) or hippuric, oxalic, and glycolic acids (from ethylene glycol)— cause a severe metabolic acidosis and can lead to coma and blindness (in the case of formic acid) or renal failure (from oxalic acid and glycolic acid). Initially, the patient appears drunk, but after a delay of up to several hours, a severe anion gap metabolic acidosis becomes apparent, accompanied by hyperventilation and altered mental status. Patients with meth-anol poisoning may have visual disturbances ranging from blurred vision to blindness.

Metabolism of ethylene glycol and methanol to their toxic prod-ucts can be blocked by inhibiting the enzyme alcohol dehydrogenase

IRON & OTHER METALS

Iron is widely used in over-the-counter vitamin preparations and is a leading cause of childhood poisoning deaths. As few as 10–12 prenatal multivitamins with iron may cause serious illness in a small child. Poisoning with other metals (lead, mercury, arsenic) is also important, especially in industry.

OPIOIDS

Opioids (opium, morphine, heroin, meperidine, methadone, etc) are common drugs of abuse, and over-dose is a common result of using the poorly standardized prepara-tions sold on the street.