Indicated for: poisoning
Route of administration: infusion
Substance: fomepizole (antidote)
ATC: V03AB34 (Various | All other therapeutic products | Antidotes)
Fomepizole is an antidote used in emergencies for poisoning with ethylene glycol, such as antifreeze, or methanol, which may be present in some industrial or household fluids. These poisonings can cause severe acidosis, kidney injury, visual problems, coma or death. Treatment should start quickly, even when ingestion is only strongly suspected.
Fomepizole blocks alcohol dehydrogenase, the enzyme that converts ethylene glycol and methanol into toxic metabolites. By slowing this conversion, it gives the body more time to clear the substance and allows clinicians to correct dangerous imbalances. In severe cases, it is used together with haemodialysis to remove the poison and its metabolites from the blood.
The medicine is given intravenously in hospital, usually in an emergency department or intensive care unit. Doses are repeated at intervals set by the doctor and may be adjusted during dialysis. Frequent blood tests are needed to check pH, electrolytes, kidney function, toxic alcohol levels and sometimes vision. Patients should not drive or drink alcohol during this period.
Possible side effects include headache, nausea, dizziness, drowsiness, unpleasant taste, infusion-site reactions or raised liver enzymes. Tell staff immediately about a widespread rash, breathing difficulty, swelling, worsening confusion, seizures or changes in vision. Fomepizole does not replace toxicology assessment, dialysis or supportive treatment when these are required.