Comparative pharmacokinetics of difethialone stereoisomers in male and female rats and mice: development of an intra- and inter-species model to predict the suitable formulation mix

Abstract

The ecotoxicity of anticoagulants used for rodent pests' management is a major concern, particularly with second generation anticoagulants, which are more persistent in the body of rodents and therefore more likely to cause secondary exposure in their predators. One of the solutions envisaged to mitigate this risk is to use stereoisomers of these anticoagulants, each of which has particular pharmacokinetics. However, the few studies published to date have considered only one species and one sex. Here, we study the pharmacokinetics of the 4 stereoisomers of 3.4 mg/kg of difethialone in rats (Rattus norvegicus) and 3 mg/kg in mice (Mus musculus) in both sexes and propose a model to choose the optimal stereoisomer efficacy/ecotoxicity mixture for the management of all these animals. Our results show that while the most persistent stereoisomer (E3-cis) is common to both species and sexes, the pharmacokinetics of the other stereoisomers show marked differences between sexes and species. Thus, the area under curve (AUC) of E4-trans in male rats is four times lower than in females or mice, making it a priori unusable in male rats. Conversely, our modeling seems to show that the E1-trans stereoisomer seems to offer the best compromise AUC persistence. In conclusion, we highlight that studies on anticoagulants must necessarily integrate research on the effect of gender and species both on efficacy and with regard to the ecotoxicity of these molecules.

Calcium-Alginate-Chitosan Nanoparticle as a Potential Solution for Pesticide Removal, a Computational Approach

“…The major problem with the use of this compound is that it produces secondary intoxication in other animals. Domestic and wild animals may repeatedly eat contaminated rodents, causing poisoning [ 80 ].…”

Weasel exposure to the anticoagulant rodenticide bromadiolone in agrarian landscapes of southwestern Europe

“…Their reduced half-life in livers of rodents apparently limits the potential exposure/bioaccumulation in a range of mammal and raptor predatory species (this study, Fourel et al, 2021Fourel et al, , 2018Fourel et al, , 2017a. The best compromise between efficacy and ecotoxicity must be searched, considering the variation due to several factors (e.g., species and sex, observed with different difethialone stereoisomers) (Rached et al, 2022).…”

Interest of the faecal and plasma matrix for monitoring the exposure of wildlife or domestic animals to anticoagulant rodenticides

“…This finding is not surprising since the metabolism of xenobiotics is known to be largely sex-dependent [58][59][60] . This difference was recently illustrated for difethialone [61]. The third factor seems to be the ingested dose with possibly a rate of elimination depending on this concentration.…”