Appearing Nov. 23 as an advance online publication of the peer-reviewed journal Neuropsychopharmacology, the study finds bupropion blunts the methamphetamine "high" and reduces cravings prompted by visual cues such as ambient drug use.
The research team hypothesizes that bupropion reduces the effects of methamphetamine by preventing the drug from entering brain cells, where methamphetamine can produce release of neurotransmitters that cause feelings of euphoria.
The study is the first to examine the effectiveness of bupropion for treating methamphetamine addiction in humans. A multisite Phase II clinical trial led by UCLA researchers is in progress.
"Finding new, effective ways to treat methamphetamine addiction is a key component of bringing the ongoing epidemic of abuse under control," said Dr. Thomas F. Newton, the study's principal investigator and professor at the Semel Institute for Neuroscience and Human Behavior.
"Bupropion's novel effect on the brain is what makes this line of research so promising," added Newton, who also is a professor of psychiatry and biobehavioral sciences at the David Geffen School of Medicine at UCLA. "These findings may point the way toward medications with even greater potential to be helpful."
Twenty of 26 participants enrolled in the project completed the study. Participants were active methamphetamine users between ages 18 and 45. Researchers randomly assigned each participant to receive treatment either with a placebo -- an inactive ingredient such as a sugar pill -- or bupropion.
Each participant received a series of three intravenous doses of methamphetamine as the study began and a second, identical series of doses six days after treatment with placebo or bupropion began.
Using a variety of subjective rating scales and questionnaires, participants reported on the subjective effects of the methamphetamine use at baseline and again after treatment with placebo or bupropion. Subjects who took the medication reported a lesser high after treatment.
Each set of research subjects reported similarly on cravings, both at baseline and after treatment, after watching a video with actors portraying methamphetamine use. Subjects who took bupropion reported less intense craving.
The study was funded by the National Institute on Drug Abuse. Other members of the research team included Richard De La Garza II and Timothy Fong of UCLA's Semel Institute and Geffen School of Medicine; John D. Roache and Christopher L. Wallace of the University of Texas Health Science Center at San Antonio; and Shou-Hua Li, Ahmed Elkashef, Nora Chiang and Roberta Kahn at the National Institute on Drug Abuse in Bethesda, Md.
Online resources:
• Semel Institute: http://www.npi.ucla.edu/.
• Geffen School of Medicine: http://www.medsch.ucla.edu/.
• National Institute on Drug Abuse: http://www.nida.nih.gov/.
• University of Texas Health Science Center at San Antonio: http://www.uthscsa.edu/.
Journal
Neuropsychopharmacology