OXFENDAZOLE

Chemistry - A benzimidazole anthelmintic, oxfendazole occurs as white or almost white powderpossessing a characteristic odor. It is practically insoluble in water. Oxfendazole is the sulfoxidemetabolite of fenbendazole.

Storage, Stability, Compatibility

Unless otherwise directed by the manufacturer, oxfendazoleproducts should be stored at room temperature and protected from light. The manufacturer recommends discarding any unused suspension 24 hours after it has been reconstituted.
Uses, Indications - Oxfendazole is indicated (labeled) for the removal of the following parasites inhorses: large roundworms (Parascaris equorum), large strongyles (S. edentatus, S. equinus, S.vulgaris), small strongyles and pinworms (Oxyuris equi).
Oxfendazole has also been used in cattle, sheep, goats, and swine; see Dosage section for moreinformation.

Pharmacokinetics - OXFENDAZOLE

Limited information is available regarding this compound's pharmacokinetics. Unlike most of the other benzimidazole compounds, oxfendazole is absorbed more readilyfrom the GI tract. The elimination half-life has been reported to be about 7.5 hours in sheep and5.25 hours in goats. Absorbed oxfendazole is metabolized (and vice-versa) to the active compound, fenbendazole (sulfoxide) and the sulfone.
Contraindications/Precautions - There are no contraindications to using this drug in horses, butit is recommended to use oxfendazole cautiously in debilitated or sick horses. Oxfendazole may besafely used in pregnant mares and foals.

Adverse Effects, Warnings

When used as labeled, it is unlikely any adverse effects will benoted. Hypersensitivity reactions secondary to antigen release by dying parasites are theoreticallypossible, particularly at high dosages.
Overdosage/Toxicity - Doses of 10 times those recommended elicited no adverse reactions inhorses tested. It is unlikely that this compound would cause serious toxicity when given alone.

Drug Interactions

Oxfendazole or fenbendazole should not be given concurrently with thebromsalan flukicides (Dibromsalan, Tribromsalan). Abortions in cattle and death in sheephave been reported after using these compounds together.