Effects of bromadiolone poisoning on the central nervous system

Toxicology of chemical biocides: Anticoagulant rodenticides - Beyond hemostasis disturbance

The use of anticoagulant rodenticides (ARs) is one of the most commonly employed management methods for pest rodents. ARs compete with vitamin K (VK) required for the synthesis of blood clotting factors in the liver, resulting in inhibition of blood coagulation and often animal death due to hemorrhage. Besides rodents (target species), ARs may affect non-target animal species and humans. Out of hemostasis disturbance, the effects of ARs may be related to the inhibition of proteins that require VK for their synthesis but are not involved in the coagulation process, to their direct cytotoxicity, and their pro-oxidant/proinflammatory activity. A survey of the cellular and molecular mechanisms of these sublethal/asymptomatic AR effects is given in this review. Data from field, clinical, and experimental studies are presented. Knowledge of these mechanisms might improve hazard characterization and identification of potential ecotoxicological risks associated with ARs, contributing to a safer use of these chemicals.

Reversible leukoencephalopathy caused by 2 rodenticides bromadiolone and fluoroacetamide: A case report and literature review

RATIONALE

With the easy access, rodenticide poisoning has been a public health problem in many countries. Characteristics of central nervous system (CNS) lesions induced by rodenticides are scarcely reported.

PATIENT CONCERNS

We presented a case of a 40-year-old man with seizure and consciousness disorder, coagulation dysfunction, and symmetric lesions in white matter and corpus callosum.

DIAGNOSIS

He was diagnosed with rodenticide poisoning due to bromadiolone and fluoroacetamide.

INTERVENTIONS

He was treated with vitamin K, hemoperfusion, acetamide, and calcium gluconate.

OUTCOMES

His leukoencephalopathy was reversed rapidly with the improvement of clinical symptoms.

LESSONS

This report presented the impact of rodenticide poisoning on CNS and the dynamic changes of brain lesions, and highlighted the importance of timely targeted treatments.

Acute toxic encephalopathy following bromadiolone intoxication: a case report

Background

Clinically, bromadiolone poisoning is characterized by severe bleeding complications in various organs and tissues. Bromadiolone-induced toxic encephalopathy is extremely rare. Here, we report a special case of bromadiolone-induced reversible toxic encephalopathy in a patient who had symmetrical lesions in the deep white matter.

Case presentation

A 23-year-old woman mainly presented with dizziness, fatigue, alalia and unsteady gait after the ingestion of bromadiolone. The laboratory examinations showed normal coagulation levels. Brain magnetic resonance imaging (MRI) showed apparent diffusion restriction in the bilateral deep white matter. The clinical manifestations and MRI alterations were reversible within one month of treatment with vitamin K. The neuropsychological assessment showed no neurodegenerative changes at the 2-year follow-up.

Conclusion

With the increased use of bromadiolone as a rodenticide, more cases of ingestion have been reported annually over the past several years. Bromadiolone-induced toxic encephalopathy has no special clinical manifestations and is potentially reversible with timely treatment. Because of the reversible restricted diffusion on diffusion-weighted images (DWI) and low apparent diffusion coefficient (ADC) values, transient intramyelinic cytotoxic oedema is thought to be the cause rather than persistent ischaemia. The underlying pathophysiological mechanism is still unknown and may be coagulant-independent. This clinical case extends the current knowledge about neurotoxicity in cases of bromadiolone poisoning and indicates that MRI is useful for the early detection of bromadiolone-induced toxic encephalopathy.

Effects of vitamin K1 treatment on plasma concentrations of long-acting anticoagulant rodenticide enantiomers following inhalation of contaminated synthetic cannabinoids

Background: An outbreak of synthetic cannabinoid (SC)-associated coagulopathy and bleeding in Illinois, USA was determined to be due to inhalation of SC contaminated with brodifacoum (BDF), difenacoum (DiF), and bromadiolone (BDL), highly potent long-acting anticoagulant rodenticides (LAARs). Treatment with high-dose vitamin K1 (VK1) prevented mortality; however, plasma LAAR levels were not measured risking recurrence of coagulopathy and bleeding due to premature discontinuation. The goal of this study was to determine if plasma LAAR levels were reduced following standard of care treatment to normalize coagulopathy.Methods: Blood samples were collected from a cohort of 32 patients, and ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis used to quantify plasma LAAR levels including enantiomers.Results: BDF was detected in 31 samples; 30 also contained DiF and 18 contained BDL. Initial plasma levels were 581 ± 87, 11.0 ± 1.9, and 14.9 ± 5.9 ng/mL for BDF, DiF, and BDL, respectively (mean ± SE). At discharge plasma, BDF levels remained elevated at 453 ± 68 ng/mL. Plasma half-lives for BDF, DiF, and BDL were 7.5 ± 1.3, 7.2 ± 1.9, and 1.8 ± 0.3 days, respectively. The half-life for trans-BDF enantiomers (5.7 ± 0.8 days) was shorter than for cis-enantiomers (7.6 ± 1.9 days). BDF half-lives were shorter, and coagulopathy normalized faster in patients receiving intravenous VK1 as compared to oral VK1. Patients prescribed VK1 at discharge had fewer re-admittances.Conclusions: These results demonstrate that plasma LAAR levels at discharge were elevated in poisoned patients despite normal coagulation, and that the route of VK1 administration affected LAAR pharmacokinetics and INR normalization. We propose plasma LAAR levels and coagulation be monitored concomitantly during follow-up of patients with LAAR poisoning. KEY POINTSIn patients treated with high-dose vitamin K1 for LAAR poisoning, plasma levels remained 40-fold above safe levels upon discharge from hospital.LAAR half-lives, normalization of coagulopathy, and readmittances were reduced by treatment with intravenous vitamin K1.

Adherence to Long-Term Follow-Up of Patients with Life-Threatening, Inhaled Synthetic Cannabinoids-Associated Coagulopathy in Chicago

A large-scale outbreak of life-threatening, inhaled synthetic cannabinoids (Spice/K2)-associated coagulopathy with bleeding complications was recently reported in Illinois. The causative agents were brodifacoum, difenacoum, and bromadiolone, potent, long-acting, 4-hydroxycoumarin anticoagulant rodenticides (LAAR) that were mixed with Spice/K2 products procured and then inhaled by the victims. We report on 3 poisoned patients who reside in underserved, socioeconomically disadvantaged neighborhoods of Chicago that were admitted and treated successfully at two inner-city, tertiary care hospitals in Chicago. The patients were discharged from the hospitals on daily long-term high-dose oral vitamin K₁ (VK₁), provided free of charge. However, 2 patients were lost to follow-up prior to safe discontinuation of oral VK₁ therapy. The third patient was treated and followed successfully for 7 months when VK₁ was discontinued. We conclude that prolonged oral VK₁ therapy and follow-up of acute, life-threatening LAAR poisoning are variable and present challenges to healthcare providers. Appropriate practice guidelines to improve patient access and adherence to daily high-dose oral VK₁ therapy and follow-up should be developed and implemented.