Intervention: Ibudilast
Trial phase: Phase 2
ATC code: R03DC04
SMILES: CC(C)C(=O)c1c(C(C)C)nn2ccccc12
Sex: All
Age groups: Adult
Healthy volunteers: Accepts Healthy Volunteers
Participants at risk: 15
Group description: This group will receive a high dose of AV411

AV411: Placebo, low, and high dose of AV411 will be administered orally BID for two consecutive weeks
Eligibility criteria:
Inclusion Criteria:

Adults between the ages of 21 and 45
Current dependence on heroin according to (Diagnostic and Statistical Manual) DSM-IV criteria
Non-treatment seeking

Exclusion Criteria:

Female participants who are currently pregnant or breastfeeding. Lack of effective birth control 10 days before Study Day 1 (15 days prior to the first PET scan)
Self-reported use of methadone, buprenorphine, or levo-alpha-acetylmethadol (LAAM) in the past 14 days
Participants who have a positive history of neurological illness (including epilepsy) or those who have received anti-convulsant therapy during the past 5 years
Liver disease requiring medication or medical treatment, and/or aspartate or alanine aminotransferase levels greater than 3 times the upper limit of normal
Gastrointestinal or renal disease that would significantly impair absorption, metabolism or excretion of study drug, or require medication or medical treatment
Neurological or psychiatric disorders including psychosis, bipolar disorder, organic brain disease, any seizure history or other disorders that require treatment or that could make study compliance difficult
Positive tuberculosis (PPD) TB skin test along with a clinical history and chest X-ray indicative of active tuberculosis. (Individuals who have a positive PPD test and have a negative chest X-ray, are not symptomatic for tuberculosis, and do not require anti-tuberculosis therapy will be eligible to participate. Participants will be asked if they ever tested positive for tuberculosis. If so, they will not be given a PPD and a chest X-ray and clinical history will be used for evaluation purposes).
Presence or positive history of severe medical illness or any cardiovascular disease or heart abnormality, such as low hemoglobin (Hb < 13 g/dL in males, Hb < 11 g/dL in females), or BP > 150/90.
Requirement for any of the following medications (current or within the past 4 weeks): psychotropics (including sedative/hypnotics, antidepressants, neuroleptics), anticonvulsants, antihypertensives, antiarrhythmics, or antiretroviral medications,. Participants on any current psychoactive prescription medications will be excluded.
Current dependence (by DSM-IV criteria) on methadone, LAAM, or buprenorphine
Participants for whom detoxification is not "clinically recommended" such as those with a significant history of overdose following detoxification
Participation in an investigational drug study within the past 3 months
Hypersensitivity to any of the medications used in this study
Participants who are positive for HIV or chronic active hepatitis
Metal implants or paramagnetic objects contained within the body which may interfere with the MRI scan, as determined in consultation with a neuroradiologist and according to the guidelines set forth in the following reference book commonly used by neuroradiologists: "Guide to MR procedures and metallic objects" Shellock Frank G., Lippincott Williams & Wilkins Healthcare, Philadelphia, 2001.
Lifetime exposure to radiation in the workplace, or participation in nuclear medicine procedures, including research protocols, in the past year
Positive Allen Test indicating lack of collateral blood flow to hand
History of Reynaud's syndrome