An outbreak of severe coagulopathy from synthetic cannabinoids tainted with Long-Acting anticoagulant rodenticides

Abstract

Objective: To describe a large regional poison center’s experience managing an outbreak of long-acting anticoagulant rodenticide (LAAR) poisoning associated with synthetic cannabinoid (SC) use.

Methods: This is a retrospective review of exposures reported to the Illinois Poison Center between March 10 and August 1, 2018. All cases coded as exposure to Δ9-tetrahydrocannabinol homologs were identified. Patients with suspected SC use, positive LAAR testing, and coagulopathy (signs or symptoms of bleeding or international normalized ratio [INR] > 2) were included. If confirmatory LAAR testing was performed and resulted as negative, the patient was excluded from this analysis. In the absence of LAAR testing, patients with suspected SC use, an INR >2, and no alternative explanation of coagulopathy were included. Suspected SC use was defined as use suspected by a member of the treating team or reported by the patient. Presenting signs and symptoms, laboratory findings, management, healthcare utilization, outcomes, and disposition of patients affected by this outbreak were reported.

Results: One hundred seventy-eight cases met inclusion criteria. Most patients were male (73%) and young to middle-aged (median age 32, IQR 25–40). Most presented to hospitals in Peoria (35%) and Cook (31%) counties. Median hospitalization was three days (IQR 2–4). Eighty-eight percent of patients presented with an INR >10. Eighteen cases had qualitative anticoagulant testing, all of which were positive for brodifacoum. Other identified LAARs included difenacoum (10/18) and bromadiolone (1/18). Sixty-three percent of patients had back, flank or abdominal pain; 70% of patients presented with hematuria. One hundred six cases received IV vitamin K₁; no adverse or anaphylactoid reactions were reported. Forty-one (22%) patients left AMA. Thirty-eight patients (21%) were re-hospitalized during the study period. Patients leaving AMA were 1.6 times more likely to be re-hospitalized than patients with other dispositions. Intracranial hemorrhage, present in 3% of total cases, was present in 4 of 5 fatalities.

Conclusions: We describe an outbreak of multiple LAARs contaminating SCs. Patients presented with bleeding from varied sites, often required blood products, factor replacement, and high dose vitamin K₁ for stabilization.

Keywords:

• Rodenticides
• brodifacoum
• synthetic cannabinoids

Acknowledgments

The authors acknowledge the Illinois Poison Center Staff and the Toxikon Consortium rotating residents and students for handling this surge of complex cases during an outbreak that lasted several months. The authors also acknowledge Jennifer Layden, MD, PhD, Connie Austin, DVM, MPH, PhD of the Illinois Department of Health, and Luke Yip, MD, and Jerry Thomas, MD from the CDC.

Author contributions

JMD and AR equally contributed to the effort as the joint first authors on the study; they conceived the study, designed the study, abstracted the data, and drafted the manuscript. LN and EM helped revise the data collection tool, cross reference mortality data with Illinois Department of Public Health data and revise the manuscript. SEA and MBM helped design the study, revise of the manuscript and provided ongoing mentorship to JMD and AR during the study process. MSW and CD searched the visual dotlab database for the cases used in the study and helped in the revision of the manuscript. TK helped in the drafting and revision of the manuscript. TMT, HDS, JL, SMB helped in the revision of the manuscript. SEA takes responsibility for the paper as a whole.

Disclosure statement

No potential conflict of interest was reported by the authors.