What is the antidote for Isoniazid (INH) poisoning?

Isoniazid (INH) poisoning can lead to severe toxicity, primarily due to its role as a potent inhibitor of vitamin B6 (pyridoxine) metabolism, which results in the depletion of this crucial nutrient. The correct antidote for Isoniazid toxicity is pyridoxine itself, as it acts to counteract the effects of the overdose by replenishing the body's stores of vitamin B6 and combatting the inhibition of pyridoxine-dependent enzymes.

In cases of severe Isoniazid poisoning, administering pyridoxine can help restore normal metabolic function, particularly in the synthesis of neurotransmitters affected by the deficiency. This is especially critical, as the symptoms of INH toxicity can include seizures, metabolic acidosis, and potentially coma, which can result from the depletion of vitamin B6.

This makes pyridoxine the cornerstone of treatment for INH overdose, aiming to alleviate the toxic effects and prevent further complications. Other choices may be effective for different types of poisoning or medical emergencies but do not serve the specific role of addressing Isoniazid toxicity directly.