ATCvet code: QP51BC03
Pharmacodynamics
Diclazuril is an anticoccidial of the benzeneacetonitrile group and has anticoccidial activity against Eimeria species. Depending on the coccidia species, diclazuril has a coccidiocidal effect on the asexual or sexual stages of the development cycle of the parasite. Diclazuril treatment will only have limited effect on the intestinal lesions caused by coccidial stages older than 16 days. Treatment with diclazuril causes interruption of the coccidial cycle and of excretion of oocysts for approximately 2 weeks. This allows the animal to bridge the period of decrease of maternal immunity (observed at approximately 4 weeks of age).
Pharmacokinetics
The absorption of diclazuril in lambs is poor after administration of the oral suspension. Following a 1 mg/kg bodyweight dose in 2-3-week-old lambs a mean maximum concentration of 301 ng/ml was obtained around 16 hours after dosing. The elimination half-life was approximately 60 hours. The oral absorption of diclazuril decreases with the animals’ age. In-vitro studies on sheep hepatocytes demonstrated that metabolic transformation of diclazuril is limited. This was equally observed in other animal species. Excretion occurs almost completely via the faeces. When diclazuril is administered in oral suspension to calves, its absorption is poor. Following a 1 mg/kg bodyweight dose in young calves a mean maximum concentration of 117 ng/ml was obtained around 16 hours after dosing. The elimination half-life was approximately 15 hours.
Environmental properties
Diclazuril has been shown to be very persistent in soil.