"Spice" is a synthetic, legal form of marijuana labeled "not for human consumption," but young people are smoking it to get high. (credit: CBS)

DENVER (CBS4) – Health officials are continuing to see people being hospitalized with a bad reaction after taking “Spice.”

Police believe a bad batch of Spice is making its way around the Denver metro area and was responsible for sending dozens to the hospital last week. Just over the weekend at least another six people experienced a dangerous reaction to the drug.

“Spice,” “K2” or “Black Mamba” are the names of a drug that is a form of synthetic marijuana. The drug is distributed in little packets. It can be 800 times more potent than THC the chemical in marijuana that makes you high.

Police believe that a bad batch of the synthetic drug is being spread around and has left more than 60 people in area emergency rooms. Several of those are on life support.

“They’re getting into something more dangerous, more potent than what we’ve seen in the past and these patients are getting a lot sicker,” said University Hospital toxicologist Dr. Kennon Heard.

Heard said all of the patients said they took “Black Mamba.”

Synthetic marijuana has been banned in Colorado. It’s made in underground labs so its potency and effects differ from batch to batch.

“Nobody knows what the effects are going to be until the first person uses it,” said Heard.

At University Hospital those hospitalized for using the drug are having seizures. Many are in comas and several are on life support.

Denver Health Medical Center said several patients have been admitted after they arrive screaming and violent.

“The predominant thing we see is patients completely out of control,” said Heard.

While the Drug Enforcement Administration outlawed many of the chemicals previously used to make synthetic marijuana, manufacturers are creating new ones to get around the law.

“What it seems like is somebody made a new drug and released it as this “Black Mamba,” said Heard. “I would not be surprised if we have someone who dies from using this product.”

Doctors at University Hospital are especially concerned because this weekend a Phish concert is scheduled at Dick’s Sporting Goods Park which has a reputation for attracting a pot smoking crowd.

While there are no statistics on how prevalent the drug is in Colorado the North Metro Drug Task Force said it is especially popular among high school students.