Synthetic substances that mimic marijuana, cocaine and other illegal drugs are making users across the United States seriously ill, according to the American Association of Poison Control Centers.

Containers of bath salts, a synthetic cocaine, sit on a counter at Hemp's Above in Mechanicsburg, Pa. Synthetic substances that mimic marijuana, cocaine are causing seizures and hallucinations so intense that thousands of them seek help in U.S. emergency rooms. (Chris Knight/The Patriot-News/Associated Press)

The products are often packaged as incense or bath salts and can be obtained for as little as $10 at many head shops, but they are causing seizures and hallucinations and even killing some people.

At the request of The Associated Press, the poison control association analyzed nationwide figures on calls related to synthetic drugs. The findings showed a sharp increase in the number of people seeking medical attention.

At least 2,700 people have fallen ill since January, compared with fewer than 3,200 cases in all of 2010. At that pace, medical emergencies related to synthetic drugs could go up nearly fivefold by the end of the year.

"Many of the users describe extreme paranoia," said Dr. Mark Ryan, director of the Louisiana Poison Center. "The recurring theme is monsters, demons and aliens. A lot of them had suicidal thoughts."

The chemicals are suspected in at least nine U.S. deaths since last year, including that of Mike Rozga's 18-year-old son, David, an athlete and band standout from Indianola.

Death blamed on marijuana lookalike

The young man got high last June on a marijuana look-alike product called "K2" and complained to a friend "that he felt like he was in hell," his father said.

Though the teen had never suffered from depression, he went home, found a shotgun and killed himself.

"These kids weren't looking for anything bad to happen," Mike Rozga said. "The truth is they didn't know what they had gotten themselves into."

The recent surge in activity has not gone unnoticed by authorities. The Drug Enforcement Administration recently used emergency powers to outlaw five chemicals found in synthetic pot, placing them in the same category as heroin and cocaine.

But manufacturers are quick to adapt, often cranking out new formulas that are only a single molecule apart from the illegal ones.

Recreational drugs created in the laboratory have been around at least since the middle of the 20th century, when LSD was first studied. But these latest examples emerged only a few years ago, starting in Europe.

Drugs made in China, India

The products were typically made in China, India and other Asian nations and soon arrived in Britain and Germany, according to DEA spokesman Rusty Payne.

In the United States, fake marijuana was last year's big seller, marketed under brands such as "K2" or "Spice." This year, the trend is "bath salts" with names like "Purple Wave" and "Bliss."

Besides being cheap and easily obtained, they do not show up in common drug tests.

Synthetic marijuana typically involves dried plant material sprayed with one of several chemical compounds, most of which were created by a Clemson University scientist for research purposes in the 1990s. The compounds were never tested on humans.

It's packaged to look like pot, and users typically smoke it, but experts say the high is more comparable to cocaine or LSD.

The bath salts are not water-softening products at all but crystalized chemicals that are snorted, swallowed or smoked. They contain two powerful stimulants: methylenedioxypyrovalerone (or MDPV) and mephedrone, which mimic cocaine, LSD and methamphetamine.

Poison control calls rise sharply

So far in 2011, poison control centers have received nearly 1,300 calls about synthetic pot, compared with 2,874 calls for all of last year, according to the poison control center data.

Poison calls for bath salts rose at an even greater rate. The centers took 301 calls in all of 2010, but had more than 1,400 for the first three months of 2011. Most of the calls came from doctors and nurses reporting patients in emergency rooms.

"The problem is really exploding here," said Dr. Elizabeth Scharman, director of the West Virginia Poison Center. Her state had three cases of bath-salt poisoning in December.

"We've had 131 cases since Jan. 1," and one-third of those were within the past two weeks, she said late last month. A law banning bath salts and synthetic marijuana was signed Tuesday by acting Gov. Earl Ray Tomblin.

"One described it as like being on cocaine, but 10 times worse," said Anna Rouse Dulaney of the Carolinas Poison Center in Charlotte, N.C.

DEA agent Gary Boggs said users assume that the products are safe because they are available in stores, even though they are typically labeled "not for human consumption."