Fomepizole for Ethylene Glycol and Methanol Poisoning

A 35-year-old man is brought to the emergency department by his wife after ingesting automobile antifreeze in an attempt at self-harm. On presentation, the patient is somnolent. He is afebrile and has a blood pressure of 126/72 mm Hg, a pulse rate of 102 beats per minute, and a respiratory rate of 24 breaths per minute. Pulse oximetry shows a hemoglobin saturation of 97% while the patient is breathing ambient air. His physical examination is normal except for tachypnea. His serum electrolyte profile and creatinine level are normal except for a serum carbon dioxide level of 17 mmol per liter. Arterial blood gas measurement reveals a pH of 7.30. Urinalysis shows microscopic hematuria and needle-shaped crystals typical of calcium oxalate. The patient's calculated serum osmolarity is 308 mOsm per liter, and his measured serum osmolality 395 mOsm per kilogram. A medical toxicologist recommends treatment with fomepizole. Subsequently, the patient's serum ethylene glycol concentration is determined to be 580 mg per deciliter (93.4 mmol per liter).