DENVER - Colorado's health department is teaming up with the Centers for Disease Control and Prevention and with local health agencies to investigate dozens of recent hospital admissions related to synthetic marijuana use.

Three deaths may be related to the drugs, which are illegal and whose chemical content, including chemicals sprayed onto the substance, is unknown, health officials said Friday in a news release. Hospitals in the Denver and Colorado Springs metropolitan areas have reported about 75 cases of synthetic pot illness in recent weeks.

Emergency room patients often are aggressive toward caregivers, and treatment can last for days. Some users reportedly had run into traffic or jumped from heights after taking the drug.

"Several individuals were in intensive care, and three deaths are being investigated as possibly associated," the Colorado Department of Public Health and Environment said in the statement.

The CDC is sending four people for the investigation, which will look at medical charts of patients reporting the symptoms and study toxicology results. Investigators hope to determine if the same product is responsible or several products.

Synthetic pot usually consists of dried herbs sprayed with chemicals that can mimic the effects of marijuana without leaving a THC trace in urine samples.

It is sold in teabag-size packets with names such as Spice, Black Mamba, Monkey Spice, K2, Twilight and Herbal Incense, the release said.

Hospital officials say they see periodic surges in synthetic pot cases. Dr. Tisha Ghosh, interim chief medical officer for the state, urged citizens to destroy any synthetic pot they have.