Case Presentation: Our patient was a 29-year-old male with a past history of chronic marijuana use that presented to the hospital with an uncontrolled hemorrhage from his tooth. The patient tripped walking down the stairs and hit his face on a stair cracking his left upper second molar. He reported no other symptoms besides the bleeding. Notably, he did report smoking ‘new synthetic weed’ several days before the fall. Physical examination revealed normal vital signs and a cracked hemorrhaging left upper second molar. Investigations revealed a supra-therapeutic INR at 5.14, elevated PT at 29.8, and elevated PTT at 49.3. CBC was normal. CMP was normal. ETOH was normal. Reticulocytes were 1.8%. Iron profile and ferritin were normal. LDH, bilirubin, and haptoglobin were normal. The mixing study revealed a prolonged aPTT and PT which was corrected in unincubated and incubated 1:1 mixing studies with normal control plasma. The patient was given 10 mg of vitamin K and 3 units of FFP. Later that day, coagulation factor studies were ordered which were normal with a slightly decreased factor V and his vWF was normal. His hemoglobin did drop significantly the next day from 15.3 gm/dL to 8.6 gm/dL, however, his INR corrected to a normal level of 1.17 and his bleeding stopped. He was discharged after a time of observation and counseled about the dangers of using synthetic marijuana.
Discussion: There have been reported cases of vitamin K-dependent coagulopathies associated with synthetic marijuana use, which were all attributable to brodifacoum (BFC) laced into synthetic marijuana. BFC is a long-acting anti-coagulant rodenticide that is a vitamin K antagonist. The rationale for combining BFC with synthetic marijuana is because BFC is a highly lipophilic agent it interferes with the metabolism and potentiates the cannabinoid effect. The terminal half-life of BFC is approximately between 15-35 days, whereas warfarin’s half-life is 18-48 hours. The initial management of a cannabinoid-associated coagulopathy is stabilization by controlling major bleeding and correcting the underlying coagulopathy. If the patient is experiencing major bleeding, prothrombin complex concentrate or fresh frozen plasma can be administered. Patients can also be started on vitamin K. There is no current consensus on the dosing of vitamin K, and they may require long-term dosages of vitamin K because of BFC’s long half-life. Finally, in all cases, a poison control center should be contacted to report the case and discuss the management.
Conclusions: Healthcare providers must be aware of the presentation, evaluation, and management of cannabinoid-induced coagulopathies that are caused by long-acting anticoagulant rodenticides. Clinical manifestations can range from asymptomatic laboratory findings to life-threatening bleeding. Severe coagulopathies, with or without bleeding, should be quickly reversed using FFP or PCC with vitamin K and a poison control center should be contacted.