Improved regional cerebral blood flow in chronic cocaine polydrug users treated with buprenorphine

Chronic cocaine and polydrug abuse have been associated with regional abnormalities in cerebral perfusion. The authors have previously demonstrated that these abnormalities are partially reversible after drug addiction treatment with buprenorphine. This study was designed to separate the effect on cerebral perfusion of abstinence from drug use from that of buprenorphine directly.

Fifteen cocaine- and heroin-dependent men were studied with 99mTc-hexamethylpropyleneamine oxime (HMPAO) brain SPECT. The men, all part of an inpatient drug abuse treatment research program, were randomly assigned after detoxification to receive placebo or either 6 or 12 mg daily buprenorphine treatment. SPECT studies were performed at baseline, after maximum dosage was reached and after tapering off the study drug. Studies were compared visually with regard to the number and location of perfusion defects by reviewers blinded to treatment assignment.

Subjects receiving buprenorphine had a significant reduction in the number of defects per study between baseline and maximum buprenorphine dose as compared with those receiving placebo (decrease of 4 +/- 5.4 versus increase of 4.8 +/- 4.7, p = 0.006). These differences were dose-related. Improvement with buprenorphine was temporary, with return to baseline after tapering off.

Buprenorphine treatment, and not abstinence from drug use alone, leads to improvement in regional cerebral perfusion abnormalities in chronic cocaine- and heroin-dependent men.