SAN ANTONIO – The South Texas Poison Center and the San Antonio Fire Department are holding a press conference on Thursday to discuss the dangers of synthetic marijuana.

Both Fire Chief Charles Hood and David A. Miramontes MD will speak on the subject.

According to the South Texas Poison Center there has been an increase in patients brought in to at least one downtown hospital who reportedly had been using "Kush", an incredibly potent version of marijuana.

“Drug sellers are peddling a batch that is more pure than other batches,” said Shawn Varney, M.D., medical director of the South Texas Poison Center and associate professor of emergency medicine at UT Health San Antonio.

Kush according to doctors, contains concentrations of tetrahydrocannabinol (THC) up to 20 percent -- the ingredient responsible for the drug's effects. Normal marijuana typically contains 1 to 5 percent.

Known side effects include psychosis or “Zombie Trance”, combative behavior, palpitations or fast heart beats, high blood pressure, stroke symptoms, seizures and death.