Mephedrone -- an old-new drug of abuse]

New natural and synthetic compounds are continuously introduced into the illicit drug market. Their origin, composition, main and side-effects are often not exactly known by the users themselves. Thus, the control of these substances is extremely difficult.In year 2008, a new synthetic drug called mephedrone (2-metilamino-1-(4-metilfenil) propan-1-on) appeared in Hungary. This work summarizes its frequency in biological samples investigated for illicit drugs, and experiences of the medical examination of mephedrone-users.Toxicological analyses of biological samples (urine and/or blood) were carried by GC-MS at the Institute of National Toxicology and at Department of Forensic Medicine, University Szeged.Altogether 5386 samples were analyzed in 2010 (4922 in Budapest and 464 in Szeged), and mephedrone was identified in 363 cases (7%).Mephedrone is banned in Hungary since January 1st, 2011, but it still available in the illegal drug market. At present we do not have sufficient experience with its long-term effects, tolerance, addiction, withdrawal symptoms or toxic dose. Thus, it is difficult to establish whether addiction and/or mental disorder occurred.