Cocaine use in persons on methadone maintenance.

Although cocaine use had increased dramatically among all levels of society over the past several years, its use by heroin addicts has existed for decades. To determine whether the prevalence or the pattern of cocaine use changes once an addict enrolls in methadone maintenance, a survey of cocaine use among persons in methadone maintenance therapy was conducted. Of the 613 persons surveyed, 229 (37%) chose to participate, with 33 (14%) considered invalid because of incomplete responses. Of the remaining 196 (86% of the participants), 64 (33%) indicated no cocaine use prior to methadone maintenance, and 132 (67%) reported some prior use. Once treatment had begun, 9 (14%) with no history of prior use admitted to at least one event within the last 6 months, and 55 (86%) reported no use. Of those reporting use prior to methadone maintenance, 41 (31%) stopped usage and 91 (69%) continued. Of the total participants, approximately half used cocaine at least once during methadone maintenance. Among those who used cocaine before and during methadone maintenance, the predominant route of administration was parenteral, 72 (54%) and 46 (51%) participants, respectively. It should be noted that there was a net gain of 17% of patients who stopped using cocaine as a result of entering methadone maintenance. Indices of cocaine use by random urinalysis over the preceding 6 months, for the entire clinic population, revealed only 86 (14%) to 110 (18%) patients to have urine samples positive for cocaine. Although cocaine use decreased on methadone maintenance, its use is still considerable, with the pattern of use differing from the recreational cocaine use in a non-narcotic-dependent population. Random urinalysis for cocaine appears to be an insensitive indication of prevalence of use.