To describe bath salts and synthetic tetrahydrocannabinol (THC) exposures in the US from 2009 to 2012, hypothesizing a yearly increase.

All exposures reported to American Association of Poison Control Centers between January 1, 2009, and April 30, 2012, were extracted from the National Poison Data System using generic and product codes.

Bath salts and synthetic THC exposures totaled 7467 and 11 561, respectively. Bath salts exposures were 0 in 2009, 298 in 2010, and 6062 in 2011. Synthetic THC exposures were 14 in 2009, 2821 in 2010, and 6255 in 2011. First-tertile bath salts exposures were lower in 2012 (n = 1007) than in 2011 (n = 2027), and synthetic THC exposures were higher in 2012 (n = 2389) than in 2011 (n = 1888). Most exposures occurred in the midwest and southeast regions (64.8% of bath salts and 58% of synthetic THC exposures). Male subjects comprised 69% (n = 5153) of bath salts users and 74% (n = 8505) of synthetic THC users. Exposure to bath salts were highest in subjects 20-29 years of age (n = 2943), and exposure to synthetic THC was highest for subjects 13-19 years of age (n = 5349). Intentional abuse and inhalation were most common reason for and mode of exposure, respectively.

Bath salts and synthetic THC abuse increased from 2009 to 2011. Synthetic THC emerged first and has more reported exposures than bath salts. In 2012, bath salts abuse declined and synthetic marijuana abuse increased. Young men intentionally abusing the drug via inhalation make up the majority of users.