Effects of oral methamphetamine on cocaine use: A randomized, double-blind, placebo-controlled trial

Background: No medication is currently approved for the treatment of cocaine dependence, but several preclinical and clinical reports suggest agonist-like medications, e.g., amphetamine analogues, may be a productive strategy for medication development. Objective: This current proof-of-concept study sought to evaluate the safety, tolerability, and effectiveness of methamphetamine as a candidate treatment for cocaine dependence. Methods: A randomized, double-blind, placebo-controlled study served to evaluate three treatment conditions in 82 cocaine-dependent individuals: (1) placebo (0 mg, 6x/day; n = 27),(2) immediate release (IR) methamphetamine (5 mg, 6x/day; n = 30),(3) sustained release (SR) methamphetamine (30 mg first pill, 1x/day; 0 mg 5x/day; n = 25). The study employed a sequential, two-phase design (i.e., 4 weeks of medication and counseling followed by 4 weeks of medication/counseling plus a contingency management procedure). Results: Both preparation forms of methamphetamine were well-tolerated, with similar retention to placebo (0 mg, 33%; 30 mg IR, 30%, 30 mg SR, 32%). Methamphetamine SR was associated with decreased sleep and increased weight loss. Medication adherence rates were high for the first dose of the day (95%), while adherence for subsequent capsules was lower. Those in the SR condition exhibited consistently lower rates of cocaine-positive urine samples (0 mg, 60%; 30 mg IR, 66%; 30 mg SR, 29%), p < 0.0001, and reported the greatest reduction in craving for cocaine, p < 0.05. Conclusions: SR methamphetamine significantly reduced cocaine use and craving. Additional research is warranted to develop and evaluate agonist-like medications that may effectively treat cocaine dependence. (C) 2008 Elsevier Ireland Ltd. All rights reserved.