This study is a double-blind, placebo-controlled randomized clinical trial of Ibudilast (IBUD) (50mg twice a day) for the treatment of Alcohol Use Disorder (AUD). Eligible participants will undergo a 12-week medication treatment period and 5 in-person visits over 16 weeks.

The study design consists of a 12-week, double-blind, placebo-controlled randomized clinical trial of IBUD (50mg twice a day) for the treatment of AUD. The investigators will randomize 132 treatment-seekers with current AUD over the course of 4 years. Participants will complete telephone screening, followed by in-person eligibility assessment, a physical exam for medical eligibility, randomization to study medication or matched placebo, and in-person follow-up visits at 4, 8, and 12 weeks of treatment. Timeline Followback (TLFB) assessment of drinking outcomes will also occur by telephone on weeks 2, 6, and 10. A final safety check visit will occur on week 16, consisting of repeated clinical labs and electrocardiography (ECG).

Inclusion Criteria:

1. Be between the ages of 18 and 65
2. Meet current (i.e., past 12 months) Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) diagnostic criteria for alcohol use disorder moderate or severe
3. Be treatment-seeking for alcohol use disorder (AUD)
4. Report drinking at least 28 drinks per week if male (21 drinks per week if female) in the 28 days prior to consent

Exclusion Criteria:

1. Have a current (last 12 months) DSM-5 diagnosis of substance use disorder for any psychoactive substances other than alcohol and nicotine

2. Have a lifetime DSM-5 diagnosis of schizophrenia, bipolar disorder, or any psychotic disorder

3. Have a positive urine screen for narcotics, amphetamines, or sedative hypnotics;

4. Have clinically significant alcohol withdrawal symptoms as indicated by a score ≥ 10 on the Clinical Institute Withdrawal Assessment for Alcohol-Revised (CIWA-R)

5. Be pregnant, nursing, or planning to become pregnant while taking part in the study; and must agree to one of the following methods of birth control (if female), unless she or partner are surgically sterile:

   • Oral contraceptives
   • Contraceptive sponge
   • Patch
   • Double barrier
   • Intrauterine contraceptive device
   • Etonogestrel implant
   • Medroxyprogesterone acetate contraceptive injection
   • Complete abstinence from sexual intercourse
   • Hormonal vaginal contraceptive ring

6. Have a medical condition that may interfere with safe study participation (e.g., unstable cardiac, renal, or liver disease, uncontrolled hypertension or diabetes)

7. Have aspartate aminotransferase (AST), alanine transaminase (ALT), or gamma-glutamyl transferase (GGT) ≥ 3 times upper normal limit

8. Have attempted suicide in the past 3 years and/or have had serious suicidal intention or plan in the past year

9. Currently be on prescription medication that contraindicates use of ibudilast (IBUD), including alpha or beta agonists, theophylline, or other sympathomimetic

10. Currently be on any medications for AUD or any psychotropic medications (e.g., psychostimulants and benzodiazepines) with the exception of stable antidepressants (stable dose for ≥4 weeks)

11. Have any other circumstances that, in the opinion of the investigators, compromises participant safety.

Adverse event data was collected for each participant between randomization to Week 12 visit (final day of study).

The study physician (Dr. Miotto) called every participant at the end of the first week on the study medication to discuss any adverse events. Adverse events were also collected at each monthly visit and the study physician was notified of any reported adverse events.