Methadone in hair and sweat from patients in long-term maintenance therapy.

The authors refer to their experience with alternative matrices to supervise the methadone therapy of heroin abusers. For this purpose, hair, sweat, and urine samples were collected from 10 heroin addicts and from a control group and were submitted to gas chromatographic/mass spectroscopic analysis for methadone and its main metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), determination. The advantages of alternative matrices to urine samples in the supervision of methadone maintenance therapy are discussed. In particular, the detection of methadone in sweat could be a preferable option to the urine matrix as a result of the feasibility of sampling that allows noninvasive collection, which is not susceptible to adulteration. The ratio between EDDP and methadone in sweat and hair was also calculated to provide information about program agreement.