Hyperbaric Oxygen Treatment (HBOT) During Methadone Tapering

Hyperbaric Oxygen Treatment (HBOT) During Methadone Tapering in Human Subjects With Opioid Use Disorder

The aims of this study are to 1) explore the efficacy of hyperbaric oxygen therapy (HBOT) compared to sham treatment in relieving signs and symptoms (both physical and psychological) of opioid withdrawal in human subjects associated with methadone dose reductions; and 2): explore whether HBOT can increase the odds of successful methadone dose reduction in patients who are interested in tapering their opioid dose. The investigators aim to explore, through qualitative methods, individual's experiences with treatment for opioid use disorder (OUD).

The investigators will conduct a prospective, randomized, sham treatment-controlled trial to examine the efficacy of HBOT for improving signs and symptoms of opioid withdrawal in methadone-maintained OUD patients as they undergo two planned methadone dose reductions spaced two weeks apart. A participant sample size of 24 was chosen based on power analysis guided by the investigators' earlier study that indicate that clinically meaningful results can be found with a minimum of 8 per group related to variables of highest interest i.e., pain and withdrawal symptoms. Additionally to this trial, participants will be asked to partake in a semi-structured interview in which they will be asked to discuss (1) Beginning Treatment, (2) Life in Recovery, and (3) HBOT & Further Treatment.

Participants will be randomized into 1 of 2 trial arms that will receive: 1) a 2-day medically-supervised full-dose HBOT treatment, or 2) a 2-day sub-therapeutic dose HBOT condition as a placebo control. Both groups will be receiving standard of care for addiction withdrawal symptoms, as managed and provided by their clinic physician and neither the full or sub-therapeutic HBOT dose are expected to affect their ongoing treatment.

Only the HBOT personnel will be aware of the treatment assignments; the rest of the research team and participants will be blinded to condition.

Participants in the active treatment arm of the protocol will receive Hyperbaric Oxygen Treatment (HBOT) prior to and the day of medically supervised 5% methadone dose reductions while sitting in a wheelchair-accessible, multi-place sealed pressurized chamber for 90 minutes each session.

Participants in the sham condition arm of the protocol will receive Hyperbaric Oxygen Treatment (HBOT) prior to and the day of medically supervised 5% methadone dose reductions while sitting in a wheelchair-accessible, multi-place sealed pressurized chamber for 90 minutes each session receiving less than a fully pressurized 100% oxygen dose.

Self-reported opioid withdrawal symptoms will be captured using an online survey and compared from week 1 to week 4 timepoint.

Subjects will be assessed for withdrawal signs and symptoms at week 1 and compared with the end of week 4.

The study design is for two 5% methadone dose reductions spaced two weeks apart to examine whether treatment group is better able to sustain the reduction.

The investigators will capture clinical chart dose records at one month and three months from baseline to determine if change in methadone was sustained

Inclusion Criteria: Enrollment in a supervised opioid treatment program at the Spokane Regional Health District Age greater than 18 years Ability to read, speak, and write English Ability to provide written informed consent. Exclusion Criteria: Pregnancy Any other medical or psychiatric condition that the PI, Co-PI (physician of record) or the Spokane Hyperbaric Center medical director determine might compromise safe study participation in the HBOT clinic (including but not limited to active psychosis, history of frequent psychiatric hospitalizations, severe anxiety with claustrophobia, aggression) Upper respiratory infection Emphysema Air cysts in the lung History of thoracic or ear surgery Taking the medication Antabuse for alcohol addiction High fever.