Clinical Trial: Topiramate to Reduce Cocaine Dependence

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Lab Trials to Develop Medication for Cocaine Dependence

Brief Summary: Cocaine addiction is a serious health problem with no available medical treatment for preventing relapse. Topiramate, a medication which lowers dopamine levels, may have the ability to diminish cocaine cravings in addicts. The purpose of this study is to determine the effectiveness of topiramate in reducing cocaine's rewarding effects in individuals addicted to cocaine.

Detailed Summary:

GABA is an inhibitory neurotransmitter that is found primarily in the brain. High GABA levels result in low levels of dopamine, another neurotransmitter that is the brain's "feel good" chemical and which plays a primary role in cocaine drug addiction. Cravings for cocaine can be reduced by lowering dopamine levels. This makes topiramate, a GABA-altering medication, a potential treatment for cocaine addiction. This study will evaluate the subjective, behavioral, and physiological effects of topiramate in individuals addicted to cocaine.

Potential participants will initially attend a 4- to 6-hour screening session. This will include review of medical and drug histories, standardized psychological questionnaires, a physical exam, and blood collection. Eligible participants will then be admitted to the inpatient clinic. During the first day of experiment, participants will receive instructions and information about the study procedures. They will also undergo a physical exam, an electrocardiogram, standardized psychological questionnaires, and blood and urine collection. A single test dose of cocaine will be administered intravenously to all participants to ensure safety with continuation in the study. Vital signs will be monitored hourly throughout the day.

The experiment will last 25 days and will enroll 24 individuals addicted to cocaine. In this three-part experiment, participants will be admitted to the inpatient clinic for an 8-day study session. Following this session, they will be discharged from the clinic for a 1-week washout phase. Participants will then return to the inpatient clinic for another 8-day study session. The two study sessions will be identical. During both sessions, participants will first receive topiramate or placebo for 4 consecutive days. While continuing to receive topiramate or placebo,
Sponsor: Bankole Johnson

Current Primary Outcome:

  • Cocaine-induced mood changes [ Time Frame: measured throughout cocaine and topiramate testing sessions ]
  • Effects of topiramate on cognitive function [ Time Frame: measured throughout cocaine and topiramate testing sessions ]
  • Drug safety [ Time Frame: measured throughout cocaine and topiramate testing sessions ]
  • Cardiovascular response to cocaine (measured throughout cocaine and topiramate testing sessions) [ Time Frame: measured throughout cocaine and topiramate testing sessions ]


Original Primary Outcome:

  • Topiramate will be well tolerated and will dose-dependently antagonize centrally mediated cocaine-induced subjective mood changes.
  • Topiramate will not exacerbate cocaine’s pressor effects, and also to characterize topiramate’s effects on cognitive function both with and without cocaine.
  • Determine the safety of concurrent topiramate and cocaine administration, with the focus on cardiovascular responses to intravenous cocaine challenges.


Current Secondary Outcome: Physiological response (measured throughout cocaine and topiramate testing sessions) [ Time Frame: measured throughout cocaine and topiramate testing sessions ]

Original Secondary Outcome:

Information By: University of Virginia

Dates:
Date Received: September 13, 2005
Date Started: January 2007
Date Completion:
Last Updated: April 17, 2012
Last Verified: April 2012