More than 40 treated for synthetic marijuana use

Denver-area hospitals are seeing a rise in emergency cases involving synthetic marijuana, which can cause confusion, violent behavior and hallucinations.

The University of Colorado Hospital has seen about 40 patients. Denver Health and the Medical Center of Aurora also report increased cases in recent weeks, The Denver Post reported Thursday.

Patient reactions include jumping off ledges or into traffic and lashing out at first responders.

Synthetic marijuana is illegal but often is used because it can be difficult to detect in urine tests. Doctors warn it includes undisclosed chemicals that pose a danger. Treatment can last days.

Synthetic products are available online. Hospital say the recent influx of patients suggests a bad batch is circulating in the area or that chemists are producing a more dangerous strain.