ExoticRx · exoticrx.com/drugs/fomepizole-4-mp
US brand names:Antizol-Vet
Fomepizole (4-MP) is dosed at 20 mg/kg IV 20mg/kg load; 15 at 12h,24h; 5 at 36h in dogs, per ANTIZOL-VET - Fomepizole Liquid [US Product Label for Dogs]. Paladin Labs (USA), Inc; 2017. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c045b5a8-b220-4f0a-a831-155b29c19454 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.585 (2026-08-01). — Plumb's 10th ed (held) printed p.558, Fomepizole monograph; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207. Verify against current literature before clinical use.
Competitive inhibitor of alcohol dehydrogenase, preventing metabolism of ethylene glycol to toxic metabolites (glycolaldehyde, glycolic acid, oxalate).
Most effective within 8-12 hours of ethylene glycol ingestion in dogs (3 hours in cats). Cats require higher doses. Very expensive but life-saving.
Species references:All Cat (Domestic) drugsAll Dog (Domestic) drugs
Each ExoticRx dose rule is graded by the strength of its primary evidence — see the editorial process.
A dog/cat sample is shown here. Cited dosing for all 2 species — reptiles, birds, pocket pets, livestock, and equine — is free on the per-species pages above. Pro adds the weight-based calculator for every species.
| Species | Route | Dose | Frequency | Evidence | Source |
|---|---|---|---|---|---|
| Dog (Domestic) | IV | 20 mg/kg | 20mg/kg load; 15 at 12h,24h; 5 at 36h | Strong | ANTIZOL-VET - Fomepizole Liquid [US Product Label for Dogs]. Paladin Labs (USA), Inc; 2017. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=c045b5a8-b220-4f0a-a831-155b29c19454 — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.585 (2026-08-01). — Plumb's 10th ed (held) printed p.558, Fomepizole monograph; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 |
| Cat (Domestic) | IV | 125 mg/kg | Loading 125mg/kg, then 31.25mg/kg q12h x 3 doses | Moderate |
Upgrade to Pro or Student to unlock the full dose ranges and frequency for every species. The drug's mechanism, warnings, indications, and cited sources are free to read.
View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.
| Connally HE, Thrall MA, Hamar DW. Safety and efficacy of high-dose fomepizole compared with ethanol as therapy for ethylene glycol intoxication in cats. J Vet Emerg Crit Care. 2010;20(2):191-206. doi:10.1111/j.1476-4431.2009.00492.x — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.585 (2026-08-01). — Plumb's 10th ed (held) printed p.558, Fomepizole monograph; page located 2026-08-05 from the book's own running heads, and carries this exact dose under the matching species heading. — SOURCE EDITION: Plumb's Veterinary Drug Handbook — ISBN 9781394172207, https://openlibrary.org/isbn/9781394172207 |