Missouri legislators approved a ban on synthetic drugs, known as bath salts, this week. The bill also expands an existing ban on another synthetic drug called K2, to include other similar substances. The measure is awaiting the governor’s signature.

Synthetic drugs are substances that mimic the effects of marijuana, cocaine and other illegal drugs. According to The St. Louis Post-Dispatch, last year the state’s legislature passed a law that criminalized possession of K2. They expanded the law this year because a number of similar marijuana-like substances were still legal.

Synthetic drugs are causing a sharp rise in serious health problems ranging from seizures and hallucinations to death. Hospitals are seeing a rapid increase in synthetic drug users with health issues that include breathing problems, rapid heartbeats, delusions and extreme paranoia. Figures from the American Association of Poison Control Centers show at least 2,700 people have gotten sick from synthetic drugs since January, compared with fewer than 3,200 in all of 2010.