WASHINGTON – The nation is at the front-end of a potential epidemic, as synthetic marijuana and synthetic hallucinogens known as "bath salts" gain popularity, especially among youth, officials warned Feb. 16.

"There has been a shocking increase in the number of people having adverse events to these synthetic drugs," said R. Gil Kerlikowske, director of the Office of National Drug Control Policy. "We simply cannot afford to wait when it comes to safety of young people."

Synthetic drugs first gained the attention of U.S. officials and health care providers in 2010. When ingested or smoked, they can cause a variety of severe and sometimes long-last effects, including hallucinations, paranoia, and seizures.

So far there have been at least 30 deaths nationwide – including suicides – related to these drugs, estimated Mark Ryan, director of the Louisiana Poison Center. Users reportedly also have attacked paramedics and emergency department staff.

"The calls we get have been among the worst. People are desperate for help," said Deborah Anne Carr, executive director of the American Association of Poison Control Centers.

Mr. Ryan said that at his center, 90% of calls regarding synthetic drugs are placed by health care providers. In contrast, only about 20% of calls regarding other poisoning situations are placed by health care providers.

Unlike other drugs, synthetic drugs usually have an immediate and severe effect, Mr. Ryan pointed out. "So the physicians call and ask ‘What is "bath salt" and what do I do?’ "

Another complication: Synthetic drugs come in a wide range of formulations. "There are literally hundreds of these compounds," said Mr. Ryan. "[Manufacturers] may use same name and get a different compound. There’s no consistency."

According to the Monitoring the Future survey – an annual, nationally representative sample of 8th, 10th, and 12th graders conducted by the University of Michigan, Ann Arbor, and supported by the National Institute on Drug Abuse – approximately one in nine 12th graders reported that they had used "spice" or "K2" (street names for synthetic marijuana) in 2011, making synthetic marijuana the second most frequently used illicit drug after marijuana.

Poison control centers have reported sharp increases in the number of calls related to synthetic drugs. Last year, there were 6,959 calls related to synthetic marijuana and 6,138 calls related to "bath salts," compared with 2,906 and 304 calls respectively in 2010, according to the American Association of Poison Control Centers.

Synthetic marijuana and bath salts often are sold legally in retail outlets such as smoke shops, gas stations, and convenience stores, and are often labeled as herbal incense or plant food. They are frequently labeled "not for human consumption" in order mask their intended purpose and avoid regulation, according to ONDCP.

Meanwhile, lawmakers are beginning to address this new phenomenon on the federal and state level.

The Synthetic Drug Control Act (H.R. 1254), a bill to add a wide variety of synthetic cannabinoid and hallucinogenic drugs to the Controlled Substances Act, was passed by the U.S. House of Representatives at the end of last year and sent to the Senate. Mr. Kerlikowske said that he hoped that the Senate would act on the measure soon.