Critics Challenge Study That Found Little Evidence to Support Use of Cannabis

By Pat Anson, PNN Editor

Medical marijuana advocates are challenging the findings of a new study that found little clinical evidence to support the use of cannabis in treating chronic pain.

“The findings appear out of step with the real-world experience of millions of patients who have come to rely on cannabis for pain management,” said Paul Armentano, Deputy Director of NORML.

The federally-funded systematic review – essentially a study of studies – was conducted by researchers at Oregon Health & Science University (OHSU), who analyzed over 3,000 cannabis studies. They could find only 25 studies that met their criteria for review. Only placebo controlled clinical trials or observational studies lasting at least four weeks were included. The rest were deemed to be poor quality or flawed in some way.

“In general, the limited amount of evidence surprised all of us,” said lead author Marian McDonagh, PharmD, professor of medical informatics and clinical epidemiology in the OHSU School of Medicine. “With so much buzz around cannabis-related products, and the easy availability of recreational and medical marijuana in many states, consumers and patients might assume there would be more evidence about the benefits and side effects.”

‘Biased Findings’

Most of the 25 cannabis studies that met OHSU’s criteria for review were considered biased in some way — 30% of the clinical trials were considered to have “high risk of bias” and half had “medium risk of bias.”  Most of the observational studies were also considered biased.

Despite the limited evidence, the OHSU research team came to some sweeping conclusions. Their study, published in the Annals of Internal Medicine, found no evidence to support the use of cannabidiol (CBD) or cannabis leaves, buds and flowers in treating pain. Only synthetic cannabis products rich in tetrahydrocannabinol (THC) were found to provide short-term relief from neuropathic pain.

Curiously, the OHSU researchers included in their review studies that evaluated the effectiveness of dronabinol and nabilone, two cannabis-based medications that are only FDA-approved to treat nausea, vomiting and weight loss. They are not formulated to treat chronic pain. Similarly, another study looked at the effectiveness of a cannabis extract in treating muscle stiffness (spasticity) caused by multiple sclerosis.

“It would appear that authors' relatively narrow focus and emphasis on both synthetic cannabis formulations (which historically have not demonstrated similar efficacy to whole-plant cannabis) as well as upon extracts that were initially designed to target medical ailments other than pain management may have biased these findings,” Armentano said in an email to PNN. 

“Numerous controlled trials involving whole-plant cannabis and reviews of said trials have determined that there exists substantial evidence that cannabis is safe and effective in pain management, particularly for neuropathy.” 

Armentano said nearly two-thirds of people enrolled in state-run medical cannabis programs registered for the treatment of chronic pain.

“Controlled studies have further indicated that cannabinoids can act synergistically with opioids, resulting in patients requiring lower doses to achieve relief. This is likely why we now have dozens of studies finding that pain patients taking opioids who initiate medical cannabis use frequently reduce or eliminate their opioid use over time,” Armentanohe said.

More Studies Needed

The OHSU researchers say more high-quality studies are needed on the safety and efficacy of cannabis products, which are largely unregulated by the FDA.

“Cannabis products vary quite a bit in terms of their chemical composition, and this could have important effects in terms of benefits and harm to patients,” co-author Roger Chou, MD, director of OHSU’s Pacific Northwest Evidence-based Practice Center said in a press release. “That makes it tough for patients and clinicians, since the evidence for one cannabis-based product may not be the same for another.”

Chou is a controversial figure in the pain community. A prolific researcher and frequent critic of opioid prescribing, Chou co-authored the CDC’s controversial 2016 opioid guideline. Although he has acknowledged conflicts of interest, Chou remains as one of the co-authors of a revised CDC guideline, which is expected to be released later this year.

The cannabis findings are similar to those in another OHSU review, which found no clinical evidence to support the use of kratom, an herbal supplement used by millions of Americans to relieve pain, anxiety, depression and other medical conditions.     

The studies on cannabis, kratom and other plant-based treatments are potentially worth up to $1.4 million for OHSU, a public research university that the federal government often turns to for medical research. According to the website GovTribe, in the last five years OHSU has been awarded nearly $2 billion in federal research grants, much of it coming from the Agency for Healthcare Research and Quality (AHRQ).

OHSU Focused on Opioid Tapering, but at What Cost to Patients?

By Pat Anson, PNN Editor

An internal medicine clinic at Oregon Health & Science University has significantly reduced the use of opioid pain medication through the use of a review board that oversees whether prescriptions are in line with federal and state guidelines, according to a new study.

“The question was, how do clinics actually implement those guidelines in practice?” co-author Jonathan Robbins, MD, assistant professor of medicine at the OHSU School of Medicine, said in a press release. “The opioid review board was a way to turn high-level recommendations into action steps we can take in our clinic to treat patients and create a culture of safe prescribing.”

The study highlights the declining use of high dose opioids at the clinic since 2017, along with increased prescriptions for the addiction treatment drug Suboxone (buprenorphine). But critics say the research failed to address whether pain relief and quality of life improved for patients or if they suffered side effects when they were tapered to lower doses or prescribed buprenorphine.

“This is a frustratingly vague account of a practice that could have serious implications for treating a large number of people with chronic pain,” said Bob Twillman, PhD, former Executive Director of the Academy of Integrative Pain Management. 

“The summary statistics presented give us some idea about how frequently people are being tapered, and how often they are being transitioned to buprenorphine, but we really could use some better data analysis, especially with respect to outcomes,” Twillman wrote in an email. “The article continues a trend in the literature, in which an output of these interventions (i.e., the change in prescribing) is confused with an outcome (i.e., what happens to the patient as a result). Basically, the article says, ‘We decided to do this, and we think it's great.’ But there are no data presented to back that up.”

“We’ll let the article stand for itself,” is the response PNN received from Erik Robinson, a senior communications specialist at OHSU. Robinson declined a request to speak with the authors of the study and to identify members of the review board.

“The article published in the Annals of Family Medicine describes a clinical practice in general terms, and we will not engage questions about specific patient outcomes and clinical discussions among physicians,” Robinson said in an email.

‘High-Risk Cases’ Reviewed

What can be gleaned from the article is that patients with more than 6 opioid prescriptions in a 9-month period had their cases reviewed, along with those on high daily doses that exceed 90 MME (morphine milligram equivalent) or those co-prescribed benzodiazepines. The 90 MME threshold is based on a recommendation in the 2016 CDC opioid guideline.

“We combed through 14,000 patients in our clinic and developed a registry about who we’re chronically treating with opioids,” co-author Mary Pickett, MD, associate professor of medicine in the OHSU School of Medicine, said in the press release. “We picked out high-risk cases to review and invited those patients’ primary care doctors to consult with us.”

The review board initially identified 664 patients on chronic opioid therapy (COT). Three years later, there were only 458 COT patients at the clinic, the number of high-dose opioid prescriptions was reduced significantly, and buprenorphine prescriptions increased over 300 percent.  

But there is no information on how many patients experienced withdrawal, whether their pain levels and quality of life improved, or if patients were satisfied with their treatment. The study only notes that “a subset of patients have had adverse response to tapering.” Those cases were reviewed a second time, but again there are no details about patient outcomes or if the tapering was stopped..

The FDA warned in 2019 that rapid tapering or abrupt discontinuation of opioid therapy could result in serious harm to patients, including withdrawal, uncontrolled pain, psychological distress and suicide. A recent study found that tapered patients were 68% more likely to be hospitalized for withdrawal, overdose or alcohol intoxication, and twice as likely to have a mental health crisis such as depression, anxiety or suicide attempt.  

“We’re coaching primary care providers to approach this carefully, and, when necessary, slowly taper their patients,” Robbins says in the OHSU press release. “We don’t do anything abruptly, and patients have supported this careful process.”

But Twillman wonders if the tapering was voluntary and if patients agreed to have their cases reviewed. The press release mentions a waiver being signed by patients, but the study does not.

“That detail is missing from the scientific publication, and it raises a concern about the extent to which that signature is truly voluntary, or if it is coerced by a threat to stop prescribing if the waiver is not signed. What is the consequence for patients who don't sign the waiver?” asked Twillman.

“And what happens if tapering or transition to buprenorphine is recommended, and the patient doesn't agree? We've seen the dangers of involuntary tapers in several studies now, so is any tapering that happens truly voluntary, and supported appropriately with ancillary services? In sum, this article raises more questions than it answers.”

Patient Urged to Taper

“In my experience, they care more about de-prescribing than they do about their patients' individual needs,” says Emma, a patient at OHSU’s Comprehensive Pain Center who lives with an intractable pain condition. She asked that we not use her real name because she fears retaliation or being discharged from the pain clinic.

Emma gets opioids from her primary care provider, but can’t get any from the pain clinic, which she says has a strict policy against prescribing opioids at any dose.

Emma says she is constantly urged to taper by her OHSU doctor. The pain clinic emphasizes non-opioid alternative treatments such as physical therapy, acupuncture, yoga, massage and psychotherapy. 

“I’m getting pretty damn fed up with OHSU’s total lack of concern for my wellbeing. They’ve all but eliminated individualized care when it comes to the treatment of pain.”

— OHSU patient

“I told them that I had spent years trying every possible alternative, and had become suicidal due to severe untreated pain. That was when my primary doc asked me to at least consider opioids as an alternative to taking my own life. I did try them, and they gave me my functionality back,” she told PNN.

“I'm getting pretty damn fed up with OHSU's total lack of concern for my wellbeing. They've all but eliminated individualized care when it comes to the treatment of pain. And how they can label the Comprehensive Pain Center a ‘pain management clinic’ while completely eliminating an entire class of effective medications is beyond me.”

Roger Chou’s Role

Patients at OHSU’s Comprehensive Pain Center were apparently not included in the study on tapering. But they too have their cases regularly reviewed by a panel of pain management experts.

One of the experts is Roger Chou, MD, a prolific researcher and longtime critic of opioid prescribing who heads OHSU’s Pacific Northwest Evidence-based Practice Center (EPC). According to the website GovTribe, over the last five years OHSU has been awarded over $2 billion in federal grants – much of it going to the EPC to support Chou’s medical research.

In addition to his research, Chou co-authored the CDC’s 2016 opioid guideline and has collaborated on several occasions with members of Physicians for Responsible Opioid Prescribing (PROP), an anti-opioid advocacy group.

In 2019, Chou co-authored an op/ed with PROP President Dr. Jane Ballantyne and PROP board member Dr. Anna Lembke that encourages doctors to consider tapering “every patient receiving long term opioid therapy.” He also served on a state task force that supported a rigid opioid tapering policy for Medicaid patients in Oregon.

Emma considers Chou “a major player behind all of OHSU’s anti-opioid policies” and is concerned that guidelines that he helped write are being used to justify tapering.

“It’s concerning to me that they’re justifying these actions by stating that they’re ‘in alignment with the guidelines.’ So essentially, they are both creating and enforcing their own set of guidelines with no transparency and no real oversight,” she said.

Last year, the American Medical Association called for a major overhaul of the CDC guideline, saying it was clear the agency’s recommendations “harmed many patients” by setting arbitrary limits on opioids.

The CDC is currently in the process of revising and possibly expanding the guideline, with the goal of releasing a new version next year. One of the authors drafting the revised guideline is Roger Chou.

Integrative and Comprehensive Pain Management Provide Only Small Benefits

By Pat Anson, PNN Editor

As concerns rose in recent years about opioid addiction and overdoses, it became trendy for healthcare providers to offer “comprehensive” or “integrative” pain management programs to patients – usually a combination of medication, physical and behavioral therapy, lifestyle changes and alternative treatments such as massage and acupuncture.

But a new study commissioned by the Agency for Healthcare Research and Quality (AHRQ) found that integrative and comprehensive pain management provide only small improvements in pain and function for people with chronic pain.   

Researchers at Oregon Health & Science University (OHSU) reviewed 57 “fair quality” clinical studies, most involving patients with moderate chronic pain caused by fibromyalgia, osteoarthritis and musculoskeletal conditions. Although the improvements in pain and function were small and the evidence limited, researchers concluded that integrative (IPMP) and comprehensive (CPMP) pain management programs worked about as well as individual treatments.

“Our review suggested that IPMPs and CPMPs may provide small to moderate improvements in function and small improvements in pain for patients with chronic pain compared with usual care and may be more effective than some medications alone. The average improvements in function and pain in our review were consistent with those reported for other therapies for pain, including opioids for chronic pain, nonpharmacologic treatments, and surgery,” researchers found.

One of the problems researchers encountered was the mish-mash of terms used to define integrative and comprehensive pain management – such as multimodal, multidisciplinary, interdisciplinary and biopsychosocial – the meaning of which often varies from provider to provider. Researchers said there was “no firm consensus on their definition or use,” which made it harder to evaluate their effectiveness. Only a few of the reviewed studies compared treatments head-to-head and many were of poor quality.

Although none of the trials specifically included Medicare patients, researchers concluded that IPMPs and CPMPs should be more widely used to address pain in the Medicare population.   

“To the extent that programs are tailored to patients’ needs, our findings are potentially applicable to the Medicare population. Programs that address a range of biopsychosocial aspects of pain, tailor components to patient need, and coordinate care may be of particular importance in this population,” they said. 

“Although use of selected individual treatments may serve some patients, a broader range of therapies that address the full scope of biopsychosocial concerns available in formal programs may benefit others. Research in the Medicare population and in patients with a broader range of pain conditions is needed as is research on the impact of program structures, coordination methods, and components on patient outcomes. Additional evidence from primary care-based programs is particularly needed.” 

One of the co-authors of the AHRQ study is Dr. Roger Chou, a primary care physician who heads the Pacific Northwest Evidence-based Practice Center at OHSU.  Chou, who co-authored the 2016 CDC opioid guideline, is a prolific researcher who has collaborated on several occasions with members of Physicians for Responsible Opioid Prescribing (PROP), an anti-opioid advocacy group.

PROP Vice President Gary Franklin, MD, “provided input” on the AHRQ study, as well as others.

In July, Chou declared a conflict of interest and recused himself from a meeting of the CDC’s Board of Scientific Counselors, which is evaluating a revision and possible expansion of the agency’s controversial guideline. Chou’s recusal apparently applied only to that meeting, as he is one of the co-authors of the revised opioid guideline — which has yet to be released publicly — and continues his involvement in federally funded pain research. 

OHSU researchers have conducted a series of reviews on a wide variety of pain therapies for the AHRQ. According to the website GovTribe, over the last five years OHSU has been awarded over $2 billion in federal grants for medical research. 

A group of patient advocates and researchers recently called for a congressional or DOJ investigation of the CDC opioid guideline, due to Chou’s significant role in writing it and his then-undeclared conflicts of interest.

OHSU Researchers Find ‘No Evidence’ to Support Use of Kratom

By Pat Anson, PNN Editor

A federally funded review of plant-based treatments for chronic pain has yet to find adequate clinical evidence on the benefits or harms of kratom, an herbal supplement used by millions of Americans to relieve pain, anxiety, depression and other medical conditions.

In an update released this week, researchers at Oregon Health & Science University (OHSU) reported that some cannabis products provide small to moderate pain relief, a finding based on a systematic review of two dozen clinical trials of cannabis.  But no similar studies were found to support the use of kratom or any other plant.   

“No evidence on other plant-based compounds, such as kratom, met criteria for this review,” researchers said.

OHSU was awarded a contract last year by the Agency for Healthcare Research and Quality (AHRQ) to review the evidence for cannabis, kratom and other plant based treatments for chronic pain.  

Kratom comes from the leaves of the mitragyna speciosa tree in southeast Asia. Although it has been used for centuries as a natural stimulant and pain reliever, few clinical trials have been conducted to test kratom’s efficacy or safety. The few studies that have been conducted were excluded by OHSU researchers due to their size, methodology or because they weren’t published in English.

For example, a 2020 Malaysian study that found kratom provided “a substantial and statistically significant increase in pain tolerance” was excluded because the young men who participated in the one-day trial were considered an “ineligible population.” OHSU researchers excluded all studies lasting less than 4 weeks.

“The conclusion that there is no evidence to support the effects of kratom on chronic pain is absurd.”

— Mac Haddow, American Kratom Association

“Setting aside the disappointment that AHRQ does not appear to be taking the purpose of the review of plant-based compounds very seriously, the conclusion that there is no evidence to support the effects of kratom on chronic pain is absurd,” said Mac Haddow, a lobbyist for the American Kratom Association.  “It’s like denying that Chicago is a windy city because the instrument that was selected for assessing wind speed was not used.”

Haddow said the AHRQ review should be expanded to include survey results from kratom users, animal studies and other types of research that don’t rise to the level of a clinical trial.

“The review appears to be excluding any research that is not a pharmaceutical development clinical trial model that would involve controlled kratom administration in a full-blown human clinical trial,” Haddow told PNN. “The deeply embedded bias against plant-based compounds that offer potential values for addressing the opioid crisis — or even providing a non-addictive and safer alternative for the management of acute and chronic pain should be a priority for the AHRQ.”

This isn’t the first time the quality of federal research into the safety and efficacy of kratom has been questioned. In 2018, the Department of Health & Human Services quietly withdrew an FDA request to classify kratom as a Schedule I controlled substance because of “lack of evidence” it can be abused or posed a public health threat. A former HHS official recently said the FDA’s recommendation was rejected because of “embarrassingly poor evidence & data.”

$2 Billion in Federal Grants

A final report on plant-based treatments for chronic pain is expected in August. As PNN has reported, OHSU researchers have recently conducted a series of reviews on a wide variety of pain therapies for the AHRQ, which are being used by the Centers for Disease Control and Prevention to revise and possible expand its controversial 2016 opioid guideline.   

Much of that research is being led by Dr. Roger Chou, a primary care physician who heads the Pacific Northwest Evidence-based Practice Center at OHSU.  Chou, who co-authored the CDC opioid guideline, is a prolific researcher who has collaborated on several occasions with members of Physicians for Responsible Opioid Prescribing (PROP), an advocacy group that seeks to reduce the use of opioid medication.

The contract on plant-based pain treatments is potentially worth up to $1.4 million for OHSU, a public research university that the federal government often turns to for medical research. According to the website GovTribe, in the last five years OHSU has been awarded nearly $2 billion in federal research grants to study everything from cancer and contraceptives to Alzheimer’s and Parkinson’s Disease.

OHSU paid $1.3 million back to the government to settle allegations that it misused grant money in its primate research center. Although the settlement was reached in 2018, it was not made public until recently in an Inspector General’s report, according the animal rights group Rise for Animals.