Residual concentrations of the flukicidal compound triclabendazole in dairy cows’ milk and cheese

Abstract

Triclabendazole (TCBZ) is a flukicidal halogenated benzimidazole compound extensively used in veterinary medicine. Liver fluke control in lactating dairy cattle is difficult because treatment should be implemented only during the dry period to avoid milk residues. However, control in endemic areas is usually implemented as regular treatments three to four times a year, even during the lactating period. Thus, information on TCBZ milk excretion and the risk of the presence of drug residues in fluid milk and milk-derivate products is essential. The experimental aims were to evaluate the comparative disposition kinetics of TCBZ and its sulpho-metabolites in plasma and milk in lactating dairy cattle after the oral administration (12 mg kg(-1)) of TCBZ and to assess the pattern of residues in cheese made with milk from treated dairy cows. Both TCBZ sulphoxide and sulphone metabolites but not TCBZ were detected in milk (up to 36 and 144 h, respectively) and plasma (up to 144 h) after oral administration of TCBZ. Residual concentrations of TCBZ sulpho-metabolites were found in cheese made with milk from treated animals. The total average residual concentration in fresh cheese was 13.0-fold higher than that obtained in milk used for its elaboration. The high concentrations of TCBZ sulpho-metabolites recovered in fresh cheese should be seriously considered before milk from treated cows is used for making dairy products.

Effects of triclabendazole on secretion of danofloxacin and moxidectin into the milk of sheep: Role of triclabendazole metabolites as inhibitors of the ruminant ABCG2 transporter

“…However, in endemic areas, parasite control programmes are implemented as regular anthelmintic treatments, even during the lactating period (Imperiale et al, 2011). In these situations, concomitant administration of multiple drugs would be likely to lead to modifications in secretion of drugs and other ABCG2 substrates, such as some vitamins, into milk (van Herwaarden et al, 2007), with an important effect on milk quality.…”

“…Conditions for HPLC analysis of TCBZ metabolites were modified in accordance with Imperiale et al (2011). Oxibendazole (Sigma-Aldrich) was used as an internal standard and samples were extracted with acetonitrile.…”

“…infestation (Fairweather, 2009). The parent drug TCBZ is not detected in plasma or milk after its oral administration in sheep, because it is rapidly metabolised into triclabendazole sulfoxide (TCBZSO) and triclabendazole sulfone (TCBZSO 2 ) (Hennessy et al, 1987;Imperiale et al, 2011). Triclabendazole metabolites are good inhibitors of the murine and human variants of ABCG2 (Barrera et al, 2012).…”

Novelin vitrosystems for prediction of veterinary drug residues in ovine milk and dairy products

“…This makes it ideal for the cheese-making process. However, in the final dairy products, drug residues can be concentrated (De Liguoro et al 1996;Imperiale et al 2011). After treating with veterinary drugs, the risks associated with milk residues may be present, bearing in mind that the primary control of residues is by adherence to label withdrawal period statements (Imperiale et al 2009).…”

A rapid colloidal gold‐based immunochromatographic strip assay for monitoring nitroxynil in milk

“…Nitroxynil (NIT, 3‐iodo‐4‐hydro‐5‐nitrobenzonitrile), a halogenated phenol, is widely applied to control immature and adult liver flukes in cattle and sheep . Meanwhile, NIT can be firmly bound to plasma proteins with a bonding rate greater than 98%, thus it has a long half‐life time in animals . Furthermore, numerous studies have confirmed that NIT can be a persistent residue in milk .…”