Fenbendazole

Fenbendazole

Clinical data
AHFS/Drugs.com	International Drug Names
ATC code	P02CA06 (WHO) QP52AC13 (WHO)
Identifiers
IUPAC name Methyl N-(6-phenylsulfanyl-1H-benzoimidazol-2-yl)carbamate
CAS Number	43210-67-9 Y
PubChem (CID)	3334
ChemSpider	3217 Y
UNII	621BVT9M36 Y
KEGG	D04140 Y
ChEBI	CHEBI:77092 N
ChEMBL	CHEMBL37161 Y
ECHA InfoCard	100.051.024
Chemical and physical data
Formula	C15H13N3O2S
Molar mass	299.349 g/mol
3D model (Jmol)	Interactive image
SMILES O=C(OC)Nc3nc2ccc(Sc1ccccc1)cc2n3
InChI InChI=1S/C15H13N3O2S/c1-20-15(19)18-14-16-12-8-7-11(9-13(12)17-14)21-10-5-3-2-4-6-10/h2-9H,1H3,(H2,16,17,18,19) Y Key:HDDSHPAODJUKPD-UHFFFAOYSA-N Y
NY (what is this?)

Fenbendazole (Hoechst brand names Panacur and Safe-Guard, Intervet Panacur and Panacur Rabbit) is a broad spectrum benzimidazole anthelmintic used against gastrointestinal parasites including: giardia, roundworms, hookworms, whipworms, the Taenia genus of tapeworms (but not effective against Dipylidium caninum, a common dog tapeworm), pinworms, aelurostrongylus, paragonimiasis, strongyles and strongyloides and can be administered to sheep, cattle, horses, fish, dogs, cats, rabbits and seals. Drug interactions may occur if salicylanilides like dibromsalan and niclosamide are co-administered. Abortions in cattle and death in sheep have been reported.

Despite being widely used as a dewormer in many species, toxicity has been reported. Birds (storks, pink pelicans, vultures, pigeons and doves) and reptiles (vipers, turtles and tortoises) have shown toxicity associated with bone marrow suppression, intestinal crypt cell necrosis and distal villi sloughing. Abortions in domestic ruminants have been associated with concurrent use of anti-trematode therapeutic agents.

Fenbendazole is poorly absorbed from the gastrointestinal tract in most species. The LD₅₀ in laboratory animals exceeds 10 g/kg when administered orally.