Kappa Opioid Receptor Antagonism for the Tx of AUD and Comorbid PTSD

Inclusion Criteria: 1. Male or female, 18 to 70 years of age, capable of reading and understanding English, and able to provide written informed consent (i.e. no surrogate). 2. Current moderate to severe AUD as determined by MINI International Neuropsychiatric Interview for DSM-5 (MINI-5). 3. At least two recent episodes of heavy drinking (\>5 standard drinks/sessions for men and \>4 standard drinks/sessions for women) over the past 30 days, and heavy drinking pattern defined as 14 drinks per week for women and 21 drinks per week for men for at least 2 of a 4-week interval within the 90 days prior to baseline; i.e. at least Moderate Risk level on WHO category. 4. PTSD diagnosis defined by MINI-5 at screening. 5. Clinician Administered PTSD Scale for DSM-5 (CAPS-5) total score ≥26 for the past week at baseline. 6. Females of child-bearing potential must be using medically acceptable birth control (e.g. oral, implantable, injectable, or transdermal contraceptives; intrauterine device; double-barrier method) AND not be pregnant OR have plans for pregnancy or breastfeeding during the study. 7. Must have a CIWA-Ar score of \< 8 prior to randomization. 8. Willing and able to refrain from medications thought to influence alcohol consumption (other formulations of naltrexone, disulfiram, acamprosate, topiramate, ondansetron, and baclofen). 9. Willing and able to refrain from psychotropic medications: stimulants/ADHD treatment, Alzheimer's medications, antipsychotics, benzodiazepines, antianxiety medications, mood stabilizers, and other sedatives. * Notes: * Participants may continue stable dose of antidepressants, prazosin, and non-benzodiazepine hypnotics and non-benzodiazepine anxiolytics to treat PTSD or insomnia. * Stable dose is defined as taken for ≥2 months prior to randomization and current does has been stable for ≥3 weeks prior to randomization and held constant during 12 weeks of study medication.) Exclusion Criteria: 1. Current diagnosis of DSM-5 bipolar I, schizophrenia, schizoaffective, and/or major depressive disorder with psychotic features (defined by MINI-5 at screening). 2. Increased risk of suicide that necessitates inpatient treatment or warrants therapy excluded by the protocol, and/or current suicidal plan, per investigator clinical judgement, based on interview and defined on the Columbia Suicidality Severity Rating Scale (C-SSRS). 3. Treatment with trauma-focused therapy for PTSD (e.g. Cognitive Processing Therapy, Prolonged Exposure, or EMDR) within two weeks of baseline study visit. Note: Supportive psychotherapy in process for PTSD at time of Screening may be continued. 4. Current diagnosis of severe non-alcohol substance use disorder (except for caffeine and nicotine) during the preceding 1 month, based on participant screening interview. 5. Use of opioids within 2 weeks of baseline or opioid use disorder in the previous 90 days. 6. History of severe traumatic brain injury (TBI) per Ohio State University TBI Identification Method. Note: history of mild or moderate TBI is allowed. 7. Any clinically significant, uncontrolled, or medical/surgical condition that would contraindicate use of SL-BUP + XR-NTX, or limit ability to complete study assessments, including seizures (other than childhood febrile seizures), severe renal insufficiency, significant arrhythmia or heart block, heart failure, or myocardial infarction within the past 2 years, severe thrombocytopenia or hemophilia, severe hepatic failure, complete hearing loss, and/or need for surgery that might interfere with ability to participate. 8. Clinically significant laboratory abnormalities, including a thyroid stimulating hormone (TSH) \>1.5 times upper limit of normal, hyperthyroidism, and aspartate aminotransferase and/or alanine aminotransferase \> 3 times upper limit of normal; cardiovascular findings QTcF \>500 msec on electrocardiogram (ECG) or blood pressure \>190/110. 9. History of allergic reaction, bronchospasm or hypersensitivity to a naltrexone or buprenorphine. 10. Unable or unwilling to refrain from medications thought to influence alcohol consumption (see inclusion criteria above.) 11. Unable or unwilling to refrain from psychotropic medications (see inclusion criteria above); with the exception of stable doses of antidepressants, prazosin, and non-benzodiazepine hypnotics and non-benzodiazepine anxiolytics to treat PTSD or insomnia. 12. Persons who are imprisoned, of minor age, diagnosed with dementia, diagnosed with a terminal illness, or otherwise require a surrogate to provide informed consent.