Wichita ? Wichita hospitals have been reporting a recent increase in patients being treated after smoking synthetic marijuana, often called K2.

Officials at Wesley Medical Center said Wednesday the hospital had treated 15 patients with reactions to the drug since Sunday, The Wichita Eagle reported. Via Christi also reported recent cases but did not have a specific number.

Synthetic marijuana is typically sold as herbal products on the Internet under a variety of names, including synthetic marijuana, “spice,” K2, and “black mamba.” The chemicals used to make it vary greatly, so users don’t know what exactly they are getting.

Ashley Lunkenheimer, emergency department manager at Wesley, said patients this week ranged in age from 17 to 22 and have been dropped off by frightened friends. She said police sometimes find them wandering the streets.

“It’s a concern of ours any time we see a spike like this,” police Capt. Doug Nolte said. He said investigators will be trying to figure out if the K2 responsible for this week’s surge in hospital cases was brought in from elsewhere or produced locally.

“We’ve got to work through that and figure out where it’s coming from,” he said.