Topiramate to Reduce Cocaine Dependence
Condition: Cocaine-Related Disorders
MeSH terms: Cocaine-Related Disorders
Study type: Interventional
Phase: Phase 2

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 description: 
      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, participants will then also receive intravenous cocaine or placebo for
      3 consecutive days.Participants will be monitored by the study physician. Electrocardiograms
      will be used to monitor heart activity, and blood will be drawn frequently to monitor levels
      of cocaine and topiramate. Participants will complete standardized questionnaires several
      times each day to assess mood changes and cognitive function.
    

Intervention name(s): Topiramate
Intervention type(s): Drug
Intervention description(s): the maximum topiramate test dose is 200 mg/d.
Other intervention name(s): Topamax
Intervention MeSH terms: Topiramate
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Basic Science
Keywords: Cocaine Addiction; Cocaine Dependence