Factor-guided diagnosis of coagulopathy associated with coumarin-contaminated synthetic cannabinoids

Contamination of synthetic cannabinoids with toxic coumarin derivatives known as superwarfarins can induce a persistent coagulopathy. In comparison to warfarin, these derivatives have prolonged half-lives and laboratory assays for detection are not readily available in clinical practice. To our knowledge, factor-guided diagnosis of coagulopathy secondary to coumarin-contaminated synthetic cannabinoids has not been described previously. Our case report details a young adult who presented to the hospital with an acute elevation in INR without any reported past medical history or illicit substance use. Factor levels were obtained and resulted quickly revealing deficiencies in factors II, VII, IX, and X, which led to a possible diagnosis of coagulopathy secondary to coumarin-contaminated synthetic cannabinoids. Upon further questioning, the patient admitted to use of synthetic cannabinoids. A bromadiolone assay was sent for testing, which resulted positive after patient discharge. Toxic coumarin derivative assays are not immediately available for reference. Given the patient's confirmed synthetic cannabinoid consumption and the possibility of coagulopathy from coumarin-contamination, factor levels served as a guide for diagnosis and treatment prior to the confirmatory assay. Obtaining factor levels in patients with an unexplained coagulopathy and suspected cannabis or synthetic cannabinoid use may aid clinicians in a more prompt diagnosis and treatment.