Pharmacotherapeutic group: Other ectoparasiticides for topical use.
ATC vet code: QP53AX24.
The mode of action of dicyclanil is not known but it is apparently similar to that of cyromazine, a triazine derivative. Similar to the benzoylphenylureas (BPU) it interferes with moulting and pupation but without acting directly on the chitin synthesis. Dicyclanil prevents the moult from the first to the second larval instar of Lucilia spp. and Wohlfahrtia spp.
After 7 days post dosing, approximately 5% of the dose was absorbed and eliminated in urine and faeces. Systemic absorption varies with such factors as wool density and length, and sheep breed. Peak blood levels were observed between 12 and 48h post dose, accounting for <0.025 mg dicyclanil equivalents/kg.
In experimental residue depletion studies, absorbed radioactivity was widely distributed throughout the body. Highest half lives were found in liver and kidney being 13 and 10 days respectively.
In muscle, fat and wool, unchanged dicyclanil was found to be the major residue, whereas in liver and kidney the descyclopropyl dicyclanil was found to be the major residue together with unchanged dicyclanil.