Pilot Study of the Effect of Ibudilast on Neuroinflammation in Methamphetamine Users

Addiction to methamphetamine is a serious health problem in the United States. Right now, there are no medications that a doctor can give someone to help them stop using methamphetamine. More research is needed to develop drugs for methamphetamine addiction. Ibudilast (the study drug) is a drug that could help people addicted to methamphetamine.

The investigators are interested to know if the study drug can help some symptoms that methamphetamine can cause, specifically inflammation in the brain. Inflammation has been shown to affect decision-making. The study drug has anti-inflammatory properties, however it is not yet known whether the drug will reduce inflammation in the brain.

Inclusion criteria

• abstinent from all drugs except marijuana and methamphetamine and have a negative urine drug screen on test days
• Meet diagnosis for recent Methamphetamine-Use Disorder (DSM-V) or does not meet any substance-use disorders

Exclusion criteria

• Known sensitivity to ibudilast
• Left handed
• MRI contraindications
• Clinically significant neurological, endocrine, renal, hepatic, or systemic diseases that would compromise safe participation or confound outcomes
• Any psychiatric diagnoses or primary psychotic or mood disorders (past depression diagnoses allowed)
• Any drug use disorder diagnosis besides methamphetamine or tobacco
• Any recreational or prescriptive use of psychotropic medications
• Claustrophobia
• Women who are pregnant or breast-feeding
• Neurodegenerative diseases that present with neuroinflammation
• More than 4 weeks abstinent from methamphetamine
• rs6971 genotype that confers low translocator protein (TSPO) binding affinity to prevent unnecessary radiation exposure
• Liver disease requiring medication or medical treatment and/or aspartate or alanine aminotransferase levels greater than 3 times the upper limit
• Participation in any drug study in the last 3 months