More than 100 people in a Connecticut park overdose on suspected synthetic marijuana in one day, straining emergency services. Washington, D.C. sees more than 200 overdoses during the month of July.

These numbers generated headlines, but health emergencies caused by synthetic cannabinoid - also known as Spice, K2, Black Mamba, Fake Weed, or Synthetic Marijuana – are not isolated incidents. Fatalities and severe illnesses related to contaminated illegal synthetic cannabinoid products have become such a significant public health problem that the FDA has issued a warning about the health risks of using them.

Why the increase in usage?

“Though all uncontrolled substances have the potential for misuse, synthetic cannabinoids have grown in popularity as a result of availability, cost, and its chemical properties,”  said Dr. Ramesh Sawhney of the Recovery Spot, an addiction treatment facility in New York State that has seen a surge in synthetic cannabinoids users in recent years.

Individuals who ingest contaminated synthetic cannabis may experience rapid heart rate, vomiting, violent behavior and suicidal thoughts, and an increase in blood pressure, as well as reduced blood supply to the heart, kidney damage, and seizures.

A rat poison ingredient

One common contaminant is brodifacoum, a very long-acting anticoagulant commonly used in rat poison that is believed to extend the "high" users feel. Brodifacoum can cause severe bleeding - especially in people with certain pre-existing conditions or those already taking certain prescription and over-the-counter drugs. The FDA advises anyone who has used synthetic marijuana products to immediately seek medical attention if they notice signs of bleeding such as easy bruising, oozing gums, and nose bleeds.

In recent months, hundreds of individuals in about 10 states – many in the Midwest – have been hospitalized after experiencing such complications. There also have been several related deaths.

Health care providers, particularly those delivering care in emergency settings, need to be aware of these risks and consider the possibility of synthetic cannabinoid exposure when individuals present with unexplained bleeding. 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.

Getting around the regulations

The FDA’s efforts to restrict synthetic cannabinoids through the Controlled Substances Act are being thwarted by distributors who often label the products as “not for human consumption.” Additionally, some manufacturers have changed the structure of the synthetic chemicals to try and skirt legal requirements.

Individual health isn’t the only thing at stake; the nation’s blood supply could be in danger as well. Brodifacoum, which has a long half-life, has been found in donated blood products. That means the bleeding risk caused by the substance, which prevents vitamin K from being reused within the body, can persist for weeks.

The bottom line, according the FDA: since there’s no way to tell which synthetic marijuana products have been contaminated with dangerous substances, avoid using them.