Synthetic Cannabis Laced With Rat Poison a Risk to US Blood Supply, FDA Warns

Megan Brooks

July 20, 2018

Illegal synthetic cannabis products laced with rat poison continue to be sold in the United States and pose a significant health risk not only to people who use these products but also the US blood supply, the US Food and Drug Administration (FDA) said this week in an update on the ongoing problem.

Hundreds of people in about 10 states have been hospitalized with serious and sometimes fatal bleeding linked to use of synthetic cannabinoids laced with brodifacoum, a highly lethal long-acting vitamin K antagonist anticoagulant commonly used in rat poison, the agency said on July 19.

For months, the Centers for Disease Control and Prevention (CDC) and the FDA have been warning about the dangers of illegal synthetic cannabis products that are sold under names such as K2 and Spice in convenience stores and gas stations.

"But despite our efforts, certain entities continue to bypass state and federal drug laws by making and distributing these products — often marked or labeled as 'not for human consumption' — and changing the structure of the synthetic chemicals to try to skirt legal requirements," the FDA said. In some cases, makers of synthetic cannabinoids have deliberately added brodifacoum, which is thought to extend the duration of the "high."

In an advisory issued in May, the CDC said case patients have presented with a variety of signs and symptoms of coagulopathy, including bruising, nosebleeds, excessively heavy menstrual bleeding, hematemesis, hemoptysis, hematuria, flank pain, abdominal pain, and bleeding from the gums or mouth.

At the time, more than 95 biological samples from case patients tested positive for brodifacoum.

The effects of brodifacoum are treatable, and the FDA said people who use synthetic marijuana products should be vigilant for signs of bleeding and should seek immediate medical attention.

"We also want to alert health care providers, particularly those delivering care in emergency settings, to be aware of these risks and consider the possibility of synthetic cannabinoid exposure when individuals present with unexplained bleeding," the FDA said. "Standard coagulation tests, such as the prothrombin time, can be dramatically elevated in these settings, and prompt treatment with high doses of vitamin K and other supportive care can potentially be life-saving," they add.

Blood Supply at Risk

There is also growing concern about the potential contamination of donated blood products, the FDA said. The agency has received several reports of donors who used synthetic cannabinoids contaminated with brodifacoum.

Owing to its long half-life, the bleeding risk from brodifacoum can persist for weeks, the FDA said. Therefore, "potential safety concerns exist for both the blood donor and the donated blood components, given the potential impact on coagulation because of its long-acting vitamin K antagonist activity," the FDA said. The agency recently alerted blood establishments to this risk.

Given the known and unknown risks associated with these synthetic cannabinoid products, the FDA said people should be advised to avoid these products, especially since there's no way of telling which synthetic marijuana products have been contaminated brodifacoum.

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