A Study of Baclofen ER

Inclusion Criteria:

1. Physically healthy cocaine-dependent (based on DSM-IV- TR criteria) male or female
aged 18-60 yrs, voluntarily seeking treatment for cocaine dependence.

2. Females must be non-pregnant, non- lactating and either be of non-childbearing
potential (i.e. sterilized via hysterectomy or bilateral tubal ligation or at least 1
year post-menopausal) or of child bearing potential, but practicing a medically
acceptable method of birth control. Examples of medically acceptable methods for this
protocol include barrier (diaphragm or condom) with spermicide, an intrauterine
device (IUD), oral contraceptives, a levonorgestrel implant, intrauterine
progesterone contraceptive system, medroxyprogesterone acetate contraceptive
injection, and abstinence.

3. Reading level at or above eighth grade.

4. Participants provide voluntary informed consent.

5. Smoking is primary route of cocaine administration.

6. Available for an inpatient stay.

Exclusion Criteria:

1. Participation in clinical trial and receipt of investigational drug(s) during
previous 60 days, except as explicitly approved by the Principal Investigator.

2. Clinically significant cardiovascular, hematologic, hepatic, renal, neurological or
endocrinological abnormalities.

3. History of serious head trauma or injury causing loss of consciousness that lasted
more than 3 minutes or associated with skull fracture or inter-cranial bleeding or
abnormal MRI.

4. Presence of magnetically active prosthetics, plates, pins, broken needles, permanent
retainer, bullets, etc. in patient's body (unless a radiologist confirms that its
presence is unproblematic). An x-ray may be obtained to determine eligibility.

5. Claustrophobia or other medical condition that disables the participant from lying in
the MRI for approximately 60 minutes.

6. Current or prior gambling problems (assessed by participants self-report)

7. Non-removable skin patches

8. Have received medication that could interact adversely with baclofen, including
muscle relaxants (including tricyclic antidepressants), antiseizure medication, CNS
depressants (tranquilizers, sleeping pills), MAO inhibitors), within the time of
administration of study agent based on the study physician's guidance (e.g. 5 half
lives)

9. Have known or suspected hypersensitivity to baclofen.

10. Be taking baclofen for any reason currently or during the past year.