The research was prompted by other findings suggesting that BUP is less preferred in humans than heroin and may have less abuse potential than heroin or other commonly prescribed opiate medications. It also produces less respiratory depression and has other advantages over METH. The participants all had histories of heroin and intravenous cocaine use. They had been maintained on METH for 1-19 years and were recruited for a residential cocaine self-administration study. They were all maintained on 60 mg METH for up to 1.5 weeks before the 7-day changeover. The changeover involved 60, 40, 30, and 0 mg METH and then 4 and 8 mg BUP. Fifteen participants successfully completed the transfer from METH to BUP; they experienced moderate withdrawal symptoms as measured by the Subjective Opiate Withdrawal Scale. Withdrawal symptoms were the highest during the first assessment of the day, at the time of BUP administration. Their symptom scores returned to baseline 4 days after the switchover. Findings demonstrated that research volunteers in a supportive inpatient setting can be rapidly switched from high-maintenance doses of METH to BUP with an acceptable degree of tolerability. Figures and 29 references (Author abstract modified)