MINNEAPOLIS - Paramedics were the first to notice the sudden trend over the past two days. They've rushed to save three dozen people all of whom overdosed on the drug known as K2.

"This is the biggest uptick I've seen and the biggest volume we've seen in recent memory," said Dr. Ann Arens, a Hennepin County Medical Center toxicologist.

Inside HCMC, the Minnesota Poison Control Center has also fielded calls about K2, a synthetic marijuana also referred to as "spice."

Dr. Arens has handled many of the recent K2 cases coming into the emergency room.

"So these drugs act in the same part of the brain marijuana does but the effects are completely different," Arens said. "Some of the problems that we see people are described to have heart attacks, people have been described to be so agitated they need medication to help them be more sedate, people have stopped breathing and need breathing tubes to breathe for them, kidney failure."

But why a spike now in the Twin Cities?

"We don't know why. It's unclear to us why this is becoming more popular," Dr. Arens said.