Cocaine plasma concentrations in persons admitted to outpatient treatment: Relationship to treatment outcome

Nine (9) of 23 (39.1%) consecutive persons who sought outpatient treatment for chronic cocaine dependence had detectable plasma cocaine concentrations on admission which ranged from 10.0 to 639 ng/ml (mean 146.9 ± 202.2). Subjects with cocaine in their plasma demonstrated at least partial tolerance to acute cocaine effects in that there was no consistent presence of hypertension, tachycardia, accelerated speaking rate, hyperreflexia, or dilated pupil. Subjects who were admitted with cocaine in their plasma retained in treatment only 4.6 ± 4.0, compared to 13.0 ± 13.4 days among those admitted with cocaine in their plasma (P < .05). In addition, 11 of 14 (78.6%) subjects without cocaine in plasma compared to 2 of 9 (22.2%) with cocaine in plasma produced a urine void of cocaine metabolite during treatment. (P < .01)