COCAINE ABUSE IN METHADONE-MAINTENANCE PATIENTS IS ASSOCIATED WITH LOW SERUM METHADONE CONCENTRATIONS

Cocaine abuse in methadone maintenance patients has emerged as a signi ficant clinical problem. To determine if raising the daily methadone d osage is an effective way to eliminate cocaine abuse, 74 methadone mai ntenance patients maintained at daily dosages between 30 and 80 mg and who chronically abused cocaine were studied by a standard protocol. A total of 21 (28.4%) subjects ceased cocaine abuse when their methadon e dosage was progressively raised to a maximal daily dose of 160 mg. C ocaine abuse appeared to accelerate elimination of methadone, since in adequate methadone serum concentrations (below 100 ng/ml) were found i n 48 of 67 (71.6%) subjects tested 24 hours after a 100 mg oral methad one dose. Although cocaine abuse in methadone maintenance patients may respond to raising the daily methadone dosage, alternative treatments for cocaine abuse in methadone maintenance patients must be identifie d since cocaine abuse may lower serum methadone concentrations.