Is Opioid Induced Hyperalgesia a Clinical Reality?

Most “studies” and “research” and pure rantings involving chronic opioids for chronic pain mention that pain patients on high opioid doses might have (must have) hyperalgesia, meaning the opioids themselves are causing the pain. They make it sound like a known scientific fact that that OIH causes problems for many patients who take opioids. but this has *never been proven* in humans.

If you’ve been told by anyone that your pain must be hyperalgesia, you can point them to this article, which summarizes the current evidence and presents a survey that only proves that some doctors suspect it sometimes.

JPM | Free Full-Text | Opioid Induced Hyperalgesia, a Research Phenomenon or a Clinical Reality? Results of a Canadian Survey | HTML – April 2020  

Chronic Pain After Cancer: The Role of Opioids – part 1

Chronic Pain Following Treatment for Cancer: The Role of Opioids – Ballantyne – 2003 – The Oncologist – Wiley Online Library – Jane C. Ballantyne –  Dec 2003

This study was done just months after Ballantyne had authored a study claiming hyperalgesia is a common problem with continued opioid use.

Ballantyne is one of the most adamant anti-opioid zealots who now insists that “opioids are bad” under all circumstances and shouldn’t be used for chronic pain, but in 2003 she was apparently still reasonable.

Opioids are the most effective analgesics for severe pain.

…opioid tolerance, if it develops, is relatively easy to overcome, and other problems of opioid use, including substance abuse, are unlikely to be problematic.

So, in 2003, she believed that opioid use is unlikely to be problematic, a view directly opposed to her current position. We never see references to these positive findings of opioid use anymore.

Truth About the Consequences of Opiophobia

A Dose of Truth about the Consequences of Opiophobia | HCPLive – 2010 – Joel S. Hochman, MD – Jan 2010

In this old article, the author picks apart a study from 2003 which became the backbone of the claims about hyperalgesia. It’s outrageous that a study from 17 years ago is determining our pain care (or lack thereof) today.

As this decade has progressed, some legal experts assumed that as a consequence of certain tort actions (cf. Bergman v. Chin), physicians would be compelled to treat pain effectively in compliance with the community standard of care.

The “community standard of care” no longer exists for pain control because opiophobia is preventing the use of the most effective medication just because some “street drugs” of the same chemical class, like heroin or illicit fentanyl, are being abused by people who then overdose. 

Microglia and Pain

Microglia may be the missing clue to solve the opioid epidemic – Sara Whitestone – Neuroscience – Université de Bordeaux – May 2019

…neuroscientists have discovered a new therapeutic target for managing pain: microglia.

Pain, as an acute sensation, serves as a warning to help your body prevent injury or avoid further harm.

the message from your stubbed toe is forced to go through a series of checkpoints—or gates—which will either open or shut to control the intensity of pain you perceive.

When pain becomes chronic, this signaling and the gate controls go haywire. Nerves become hyper-sensitive, firing off messages to the brain even in the absence of an injury.  

Classification of Chronic Pain – IASP Pain Terminology

IASP Pain Terminology – IASP – Dec 2017

The following pain terminology is updated from “Part III: Pain Terms, A Current List with Definitions and Notes on Usage” (pp 209-214) Classification of Chronic Pain, Second Edition, IASP Task Force on Taxonomy, edited by H. Merskey and N. Bogduk, IASP Press, Seattle, ©1994.

This “dictionary” is not new, but these terms are still used and pain is no different than it was years ago.

I’m posting this because it makes the subtle distinctions clear between often misused words: allodynia and the latest fashionable, yet hypothetical syndrome of “hyperalgesia”, when pain supposedly worsens due to “too much” opioid medication. 

Little evidence of opioid-induced hyperalgesia

Evidence of opioid-induced hyperalgesia in clinical populations after chronic opioid exposure: a systematic review and meta-analysis – Br J Anaesth. – 2019 Jun

Opioid-induced hyperalgesia (OIH) is well documented in preclinical studies…

It’s such a trendy topic that I’m sure many researchers are looking for evidence that chronic pain patients only need high doses because they are suffering from “opioid-induced hyperalgesia”, which has still NOT been proven in humans.

…but findings of clinical studies are less consistent.

This isn’t surprising to most pain patients, who know the difference between their increasing pain and hyperalgesia. 

HHS Guidance for Dosage Reduction

HHS Guide for Clinicians on the Appropriate Dosage Reduction or Discontinuation of Opioid Analgesics – Oct 2019

I’m furious that throughout this detailed 8-page document, the assumption is always that tapers must happen, one way or another. I couldn’t find a single sentence suggesting it may be best to leave patients on some dose of opioids for their pain because, for most of us, opioids are the ONLY effective means of pain control.

More judicious opioid analgesic prescribing can benefit individual patients as well as public health when opioid analgesic use is limited to situations where benefits of opioids are likely to outweigh risks.

Yet they never again mention this case of the benefit being greater than risks, even though that’s the case for so many of us.

Complex Chronic Pain Disorders

Complex Chronic Pain Disorders – By Don L. Goldenberg, MD – Feb 2019

The pathophysiology of and approaches to 3 commonly seen pain conditions: CRPS, EDS, and SFN.

• Complex regional pain syndrome (CRPS),
• Ehlers-Danlos syndrome (EDS), and
• small fiber neuropathy (SFN)

are three important and complex chronic pain disorders.  

Diagnosing Hyperalgesia to Limit Care

Misuse of Hyperalgesia to Limit Care | Practical Pain Mgmt | By Donald C. Harper, MD, BSc – March 2011

John (not his real name) is a 51-year-old chronic pain patient that I have been seeing since 2003. I had begun carefully titrating him on oxycodone, Oxycontin® and Dilaudid®, which had been started by another doctor and, ultimately, settled on a dose of Oxycontin 640mg B.I.D., 32mg hydromorphone q 4 hrs prn breakthrough pain and Xanax® 1 to 1.5mg q.i.d. prn muscle spasms and anxiety. On these medicines, he was content and functional and denied any deficits or side-effects due to his medicine.

His insurance company was concerned about the expenses of his medicine and asked me to arrange for a second opinion. Given the complicating factor of his end-stage lung cancer, I arranged for an evaluation by the pain clinic of a major cancer center.  

The Truth About Hyperalgesia

Demystifying Opioid-Induced Hyperalgesia – By Jennifer P. Schneider, MD, PhD – Feb 2019

Some insurance companies have declined to continue paying for opioid medications, citing OIH. Here’s why.

In cases like these, many insurance companies state that patients should have their doses tapered in order to decrease their pain.

Now, we’re really living in a fun-house mirror world, where taking a pain reliever increases pain and taking away opioid pain relief decreases it.

However, clinicians may find that attempts to reduce the opioid dose often result in increased pain.

Ya think?