A competitive ADH inhibitor is 4- methylpyrazole, also known as foamepizole. It has been demonstrated in vitro that foamepizole [blocks alcohol dehydrogenase enzyme activity in the liver of canines, primates, and humans].Fomepizole is prescribed as an antidote for methanol or ethylene glycol poisoning or for use in cases of suspected methanol or ethylene glycol consumption, either alone or in conjunction with hemodialysis. When a patient has metabolic acidosis and a high Osmolar gap, it should be administered if toxic ethylene glycol or methanol intake is known or suspected to have taken place. Headache (14%), nausea (11%), dizziness, increased sleepiness, and unpleasant taste/metallic taste were the side effects that were described as being drug-related or having no known association. The concurrent use of fomepizole and medications that either increase or inhibit cytochrome P450 may result in reciprocal interactions. Antizol is recommended as an antidote for methanol or ethylene glycol poisoning, or for use in cases of suspected methanol or ethylene glycol consumption, either alone or in conjunction with hemodialysis.

Keywords : Antidotes, Fomepizole, ADH Inhibitor.