A 22-year-old Illinois man is dead after using synthetic marijuana laced with a chemical used in rat poison, according to a medical examiner’s office.

The Cook County Medical Examiner’s office said Friday the man died March 28 at a Chicago-area hospital. Excessive internal bleeding was found during an autopsy. The anticoagulant brodifacoum was detected during the investigation into his death.

Brodifacoum is used as an ingredient in rat poison.

“Public health agencies are reporting that patients who admitted to smoking synthetic cannabinoids are presenting to hospitals with severe bleeding and testing positive for brodifacoum,” said Dr. Ponni Arunkumar, Cook County’s Chief Medical Examiner. “Brodifacoum is a highly lethal rodenticide and should not be consumed.”

Brodifacoum, which is used as rat poison, impairs blood clotting in humans and can cause fatal gastrointestinal and intracerebral hemorrhage.

“This poisoning is unique in that its effects can last weeks to months. Symptoms may range from unexplained bruising, bleeding from the nose or gums, blood in the urine or stools, coughing up or vomiting blood, to bleeding in the brain,” said Dr. Jenny Lu, toxicologist and emergency medicine physician at Stroger Hospital. “Treatment includes a form of vitamin K, which can only be prescribed by a physician or given in the hospital and complete treatment of this poisoning involves taking high doses of this pharmaceutical grade vitamin K daily for weeks to months.”

The reported death comes less than a week after Illinois officials reported an outbreak of 89 cases since March 7 of severe bleeding linked to contaminated drugs, NBC News reported. 

“Other interventions may be necessary depending on the severity of the poisoning. As bleeding can be life-threatening, it is important that people who have used synthetic marijuana seek medical attention at the first sign of poisoning so we can begin treatment right away,” said Lu.