Methanol poisoning is classically associated with which features?

Methanol poisoning is classically associated with which features?

• A. Acute visual symptoms and severe AGMA
• B. Pancreatitis and renal toxicity
• C. Calcium oxalate nephrolithiasis
• D. Hyperkalemia

Answer: (A)

Methanol toxicity is characterized by optic nerve injury causing acute visual disturbances (ranging from blurred vision to sudden blindness) together with a severe anion gap metabolic acidosis. The key driver is formic acid, a toxic metabolite formed when methanol is processed by alcohol dehydrogenase. Formate accumulates and damages the optic nerve, while the acid buildup creates a high anion gap acidosis. Often there is also an elevated osmolar gap from unmetabolized methanol present in the blood. This combination—rapid visual impairment plus marked metabolic acidosis—is the classic clue that points to methanol rather than other alcohols. In contrast, calcium oxalate nephrolithiasis and pancreatitis are more typical of ethylene glycol poisoning, and while acidosis can occur with many conditions, hyperkalemia is not a defining feature of methanol toxicity.

Methanol toxicity is characterized by optic nerve injury causing acute visual disturbances (ranging from blurred vision to sudden blindness) together with a severe anion gap metabolic acidosis. The key driver is formic acid, a toxic metabolite formed when methanol is processed by alcohol dehydrogenase. Formate accumulates and damages the optic nerve, while the acid buildup creates a high anion gap acidosis. Often there is also an elevated osmolar gap from unmetabolized methanol present in the blood.

This combination—rapid visual impairment plus marked metabolic acidosis—is the classic clue that points to methanol rather than other alcohols. In contrast, calcium oxalate nephrolithiasis and pancreatitis are more typical of ethylene glycol poisoning, and while acidosis can occur with many conditions, hyperkalemia is not a defining feature of methanol toxicity.