Pyridoxine (Vitamin B6)
Pharmacology. Pyridoxine (vitamin B6) is a water-soluble B-complex vitamin that acts as a cofactor in many enzymatic reactions. Overdose involving isoniazid or other monomethylhydrazines (eg, Gyromitra mushrooms) may cause seizures by interfering with pyridoxine utilization in the brain, and pyridoxine given in high doses can control these seizures rapidly and may hasten consciousness. It can also correct the lactic acidosis secondary to isoniazid-induced impaired lactate metabolism. In ethylene glycol intoxication, pyridoxine may enhance metabolic conversion of the toxic metabolite glyoxylic acid to the nontoxic product glycine. Pyridoxine is well absorbed orally but usually is given intravenously for urgent uses. The biological half-life is about 15–20 days.
Indications
Acute management of seizures caused by intoxication with isoniazid (See Isoniazid (INH)), hydrazine, Gyromitra mushrooms (See Mushrooms
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