CHICAGO (CBS) — Cook County officials have confirmed a 22-year-old man who died of excessive bleeding last month is one of two deaths linked to synthetic marijuana use in recent weeks. A third possible case is awaiting toxicology results.

According to the Cook County Medical Examiner’s office, a 22-year-old man who died at Advocate Christ Medical Center on March 28 suffered excessive internal bleeding.

Although a cause of death has not yet been determined, an autopsy detected the presence of brodifacoum, a deadly anticoagulant used in rat poison, which has recently been found in several cases of synthetic marijuana use in Illinois. It can cause severe bleeding, which can be fatal.

“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. Even without symptoms, the blood’s ability to clot is severely impaired and risk of bleeding is high,” said Dr. Jenny Lu, a toxicologist and emergency medicine physician at Stroger Hospital. “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.”

The Cook County Medical Examiner’s office confirmed the 22-year-old man is one of two deaths linked to synthetic marijuana in Illinois since early March. The medical examiner is waiting for the toxicology report of another person who suffered from excessive bleeding, but that death has not yet been linked to synthetic marijuana.

According to the Illinois Department of Public Health, there have been at least 95 cases of severe bleeding after using synthetic marijuana since early March, including 26 in Chicago and 7 in suburban Cook County.

“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.”

Synthetic cannabinoids — often called Spice, K2, or fake weed — are human-made mind-altering chemicals either sprayed on dried shredded plant material, or sold as a liquid to be vaporized and inhaled. Public health officials have said the product is not safe, and if anyone has purchased it they shouldn’t use it.