This study will evaluate the efficacy of ondansetron compared with placebo in the treatment
of cocaine dependence.
Minimum age: 18 Years.
Maximum age: N/A.
- Males and females who have given written informed consent.
- Ages 18 years and above and, must weigh at least 40 Kg and no more than 140 Kg.
- Good physical health as determined by a complete physical examination, an EKG within
normal limits, and laboratory screening tests within acceptable parameters.
- Current DSM-IV diagnosis of cocaine dependence.
- At least one positive urine drug screen for cocaine at screen or baseline prior to
- The pregnancy test for females at intake must be negative.
- Literacy in English and ability to read, understand, and complete the ratings scales
and questionnaires accurately, follow instructions, and make use of the behavioral
- Answered an advertisement in the newspaper/radio/television, and expressing a wish to
stop using cocaine.
- Willing to participate in behavioral treatments for cocaine dependence.
- Current dependence, defined by DSM-IV criteria, on any psychoactive substance other
than cocaine, alcohol, nicotine, caffeine, or marijuana or physiological dependence
on alcohol requiring medical detoxification.
- Neurological or psychiatric disorders
- Any Axis 1 disorder that warrants treatment or would preclude safe participation in
- Serious medical illnesses
- Mandated by the court to obtain treatment for cocaine dependence.
- Anyone who, in the opinion of the investigator, would not be expected to complete the
study protocol because of probable incarceration or relocation from the clinic area.
- HIV with CD4 positive T cell counts <500 mm3
- Any subjects on any pharmacotherapy for the treatment of AIDS or HIV will be
- Active syphilis that has not been treated, or refused treatment for syphilis
- Severe or life-threatening adverse reactions to medications (including ondansetron)
in the past or during this clinical trial.
- Currently on active treatment with ondansetron.
- Receipt of a drug with known potential for toxicity to a major organ system within 30
days prior to study entry (e. g., isoniazid, methotrexate).
- Female subjects who are pregnant, lactating, or not adhering to an acceptable form of
contraception at any time during the study.
- Concurrent (within two weeks of randomization) regular use of psychotropics
including, but not limited to, antidepressants, anxiolytics, anti-psychotics,
anticonvulsants, and psychomotor stimulant-type medications, St. John's Wort,
yohimbine, ginkgo biloba, horehound, or any other central nervous system active
- Use of any opiate substitutes (methadone, LAAM, buprenorphine) within 1 month
- Clinically significant hematological or biochemical test results that in the view of
the study physician require immediate or urgent treatment.
- Pyrexia of unknown origin or neuroleptic malignant syndrome.
- Serious medical co-morbidity requiring medical intervention or close supervision, or
any condition that can interfere with the receipt of ondansetron.
- Received inpatient or outpatient treatment for cocaine dependence within the last 4
weeks, or previously participated in a clinical trial utilizing ondansetron.
- Electroconvulsive therapy within the 3 months preceding screening.
- Members of the same household.