Coagulopathy at intoxication with rodenticides – antagonists of vitamin K

Abstract

The review is devoted to poisoning with rodenticides containing indirect anticoagulants – vitamin K antagonists (VKA). The work describes the main groups of anticoagulants that are used in such preparations, describes the mechanism of their action. The authors analyzed a significant number of foreign and local literary sources on the poisoning of the rodenticides of this group. It was concluded that VKA intoxication occurs much less frequently than other rodenticides; it is mainly the occasional intake of drugs, most of the victims are children. The use of rodenticides-VKA by psychiatric patients and criminal cases are not common. Analysis of the literature has shown that the overwhelming number of poisonings occurs when using VKA, which are contained in ready-made rodent-control baits available to the majority of the population. Intoxication with modern rodenticides-VKA – superwarfarins is possible with oral, dermal exposure and contact with the mucous membranes of the eye; they have a cumulative effect. The main clinical manifestation of superwarfarin poisoning is hemorrhagic syndrome. The clinical signs of coagulopathy are much more pronounced in case of deliberate poisoning than in case of accidental poisoning, since for the appearance of hemorrhagic syndrome, a large amount of the substance contained in the finished bait is required. The principles and features of diagnosis, differential diagnosis and treatment of coagulopathy of this genesis are described. All patients have changes in the coagulogram, characteristic of vitamin K-dependent coagulopathy: an increase in the international normalized ratio, prothrombin time and activated partial thromboplastin time, a decrease in the levels of II, VII, IX and X blood coagulation factors, physiological anticoagulants – proteins C and S. Determine the concentration of superwarfarin in the blood using high performance liquid chromatography is not possible in every medical institution. In the clinical diagnosis of coagulopathy and the identification in the coagulogram of changes characteristic of vitamin K deficiency, even if its etiological cause has not been established, it is immediately necessary to prescribe adequate therapy: the introduction of fresh frozen plasma and/or concentrates of prothrombin complex factors, prescription of vitamin K preparations, symptomatic therapy. Taking into consideration the long half-life of superwarfarins, coagulopathy can persist for several months, during which treatment should be continued. With timely diagnosis and the appointment of adequate therapy, the prognosis in most cases is favorable. The mortality rate among people with superwarfarin poisoning is not high. As an illustration, the authors cite two clinical cases from personal practice.