to the editor: With the ease of instantaneous communication, the Internet has facilitated the introduction of a new class of drugs of abuse. Bath salts and synthetic cannabinoids are being sold in stores throughout the world, packaged for a variety of uses, and labeled as “not to be taken internally.” However, these products are being promoted online as “legal highs.”

Bath salts have already been linked to an alarming number of emergency department visits in the United States. Analysis of these white powders has identified them as mephadrone and Methylenedioxypyrovalerone (MDPV), two substances known to interfere with dopamine reuptake in areas of the brain identified as important in the development of drug dependency.¹ Their central action is similar to that of cocaine. Office-based physicians, emergency department staff, and psychiatric emergency services have witnessed an epidemic of presentations among users of these drugs with symptoms including tachycardia, chest pain, elevated blood pressure, seizures, and hallucinatory delirium with associated paranoia and violent behaviors.² Several homicides and suicides have been reported following the use of these drugs.

Although administration of bath salts is primarily by nasal insufflation, a rise in intravenous use has been described.³ Experienced users report that these substances are highly addictive. Many have described a pattern of repetitive dosing every three or four hours to maintain stimulant effect. Although outlawed in several states, they remain widely available and are now among the most popular drugs used in dance clubs in urban areas.

Marketed online as “synthetic marijuana,” synthetic cannabinoids are agonists of brain receptors that were originally developed to assist in the understanding of the cannabinoid neurotransmitter system. Information about the synthesis of these agents, generally published in specialized research-oriented journals, has been exploited by some with sufficient biochemical sophistication to manufacture these substances in unidentified overseas laboratories. These agents have a potentcy that is estimated at four to 10 times that of marijuana.⁴ Sold as “K-2” or “Spice,” these packets are widely available in local shops. Users generally smoke these products like marijuana. Anxiety, panic, palpitations, chest pain, and precipitation of schizophrenic-type psychosis have been reported in persons using these drugs.^5,6

On October 21, 2011, the U.S. Drug Enforcement Administration (DEA) used its emergency scheduling authority to ban the sale and possession of mephadrone and MDPV, chemicals commonly found in bath salts. Synthetic cannabinoids have been DEA schedule I drugs since March 1, 2011.

The manufacturing, sale, and promotion of these new substances depend heavily on information spread by electronic media. Because of their rapidly increasing prevalence, family physicians should familiarize themselves with the signs and symptoms of intoxication with these drugs and be prepared to provide early interventions and referral.