Adjunctive Hyperbaric Oxygen Eases
Opioid Withdrawal

Fran Lowry

March 09, 2020

NATIONAL HARBOR, Maryland — Adjunctive therapy with hyperbaric oxygen appears to ease withdrawal symptoms in patients on medication-assisted therapy (MAT) for opioid use disorder.

In a small pilot study, patients undergoing MAT who also received hyperbaric oxygen therapy (HBOT) experienced a greater reduction in withdrawal symptoms and were able to taper methadone doses more than their counterparts who did not receive HBOT.

Trevor Roush, Washington State U. med student

"People with opioid use disorder often cite severe withdrawal symptoms as a barrier to reducing their opioids," study investigator Trevor Roush, a third-year medical student at the Elson S. Floyd College of Medicine, Washington State University, Spokane, told Medscape Medical News.

"Pain and withdrawal symptoms in patients undergoing methadone-assisted therapy often are undertreated because pharmacological solutions such as sedatives can have deadly synergistic effects," Roush said.

The findings were presented here at the American Academy of Pain Medicine (AAPM) 2020 Annual Meeting.

Cuts Neuroinflammation

Previous preclinical work by Washington State University researchers showed HBOT suppresses naloxone-precipitated withdrawal symptoms in morphine-dependent mice.

"We noticed that the clinical withdrawal symptoms of withdrawal were lessened when we administered hyperbaric oxygen, and this prompted the current pilot study," Roush said.

Hyperbaric oxygen has been shown to help control neuroinflammation after traumatic brain injury and is typically used to help treat severe burns and inhalation poisonings. The investigators hypothesized that it may also be useful for opioid withdrawal symptoms.

The prospective randomized study included 31 adults who were undergoing MAT and wanted to taper their methadone dose. Of these participants, 17 were randomly assigned to receive HBOT and 14 to continue with MAT alone. HBOT was administered for 5 consecutive days in 90-minute sessions in a hyperbaric oxygen chamber.

Withdrawal symptoms were assessed pre- and post-HBOT sessions using the Clinical Opioid Withdrawal Scale (COWS).

The clinical response was almost immediate. The investigators found that on average, patients in the HBOT group experienced nearly a twofold reduction in withdrawal symptoms after a single session compared with controls.

The mean COWS score among patients who got HBOT at baseline was 30.6 (standard deviation [SD] 20.0]. Post-HBOT, it was 16.8 (SD 16.5) vs the control group, where the mean COWS score went from 23.4 (SD 18.5), to 17.1 (SD 13.0) post-HBOT.

At 1 month, the 14 patients remaining in the HBOT group had an average 5 mg reduction in daily methadone dose, compared to a 2.88 mg reduction in the remaining eight controls.

At 3 months, the average methadone dose reduction in the HBOT group was 4.3 mg vs an average reduction of 0.25 mg for the control group. The therapy was safe and well tolerated.

Time Commitment

The most cumbersome part of the therapy for patients is spending 90 minutes in the hyperbaric oxygen chamber, Roush said.

"But people who want to get off opioids are willing to make the trade-off. So for our cohort at least, if it meant decreasing their opioid dose, patients were willing to give it a little bit more of their time," he said.

Patients were willing to make the time commitment and "several said they wished they could have more or longer sessions," coauthor Marian Wilson, PhD, MPH, RN-BC, College of Nursing, Washington State University, added.

Treatment satisfaction scores among participants were high, Wilson noted.

"Feedback survey comments were almost entirely positive, including the belief that the treatment helped their withdrawal symptoms, pain, sleep, and mood," she said.

Roush acknowledged that the small numbers of patients included in the trial was a limitation of the study.

"We need to repeat it in a larger sample, but the research that we have done in mice, in addition to the trend of greater symptom relief in human subjects receiving HBOT, suggests that it does have efficacy in reducing symptom burden associated with opioid withdrawal," Roush said.

Commenting on the findings for Medscape Medical News, Robert Bolash, MD, Cleveland Clinic, Ohio, said he hopes the study findings prompt a much larger prospective randomized trial.

"As we consider all of the adjuncts that we have for patients to succeed with opioid reduction, employing this modality may have a role for a challenging subset of patients particularly struggling with dose reduction in the future," said Bolash.

The study was supported by Washington State University Alcohol and Drug Addiction Research Program. Roush, Wilson, and Bolash have disclosed no relevant financial relationships.

American Academy of Pain Medicine (AAPM) 2020 Annual Meeting:
Abstract 443. Presented February 29, 2020.

For more Medscape Neurology news, join us on Facebook and Twitter


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.