CHICAGO (CBS)–The death of a 25-year-old Chicago man last month has been tied to synthetic marijuana use. 

The Cook County Medical Examiner’s Office reported Monday that a chemical commonly used to make synthetic marijuana contributed to the death of Jorge Vega.

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

The Brighton Park resident died June 12 at Loyola University Medical Center in Maywood.

Vega’s death was at least the fifth death tied to synthetic marijuana use in Cook County, according to statistics from the Illinois Department of Public Health.