Prescription opioid medications are commonly used in the U.S. as treatments for medically serious pain.…
Brain Changes Can Make Opioid Abusers Extra Sensitive to Pain
People with a history of opioid misuse may undergo chemical and structural changes in their brains that make them more sensitive to pain, new research has found.
Many of the people who develop opioid use disorder (opioid abuse and/or opioid addiction) consume opioid medications that were originally prescribed for the management of moderate or severe pain. Unfortunately, pain often continues to affect these individuals after they begin experiencing diagnosable substance problems. In a study review published in November 2014 in the journal Drug and Alcohol Dependence, researchers from two American universities examined the issues that face physicians who must try to address ongoing pain in people affected by the symptoms of opioid use disorder.
Opioids and Pain Management
The presence of ongoing or recurring pain can seriously limit a person’s ability to live a fulfilling life or maintain an independence-sustaining daily routine. Doctors commonly use the term pain management to describe the approach required to help people cope with pain and remain functional. There are a range of non-opioid-related options for helping people manage their pain. Examples of these options include non-opioid medications (e.g., acetaminophen and nonsteroidal anti-inflammatory drugs or NSAIDs), physical therapy, exercise, electrical nerve stimulation, cognitive behavioral therapy, biofeedback and acupuncture. However, for people dealing with certain types of moderate or severe pain, opioid medications are often part of the preferred course of treatment.
Examples of opioid medications commonly used in short-term pain treatment or ongoing pain management include hydrocodone (e.g., Vicodin and Lortab), oxycodone (e.g., OxyContin and Percodan), fentanyl (e.g., Duragesic), hydromorphone (e.g., Dilaudid) and morphine (e.g., Kadian and Avinza). All of these substances reach the brain in roughly the same way and, in addition to diminishing the brain’s pain sensitivity, trigger a feeling called euphoria by altering the chemical balance in an area known informally as the pleasure center. Opioid medications also slow down the baseline activity rate in both the brain and the spinal cord (the two organs that form the central nervous system).
Opioid Use Disorder
A person with opioid use disorder has symptoms that indicate the presence of life-impairing abuse of an opioid substance, the presence of opioid dependence/addiction or the presence of a combination of abuse and addiction. Minimally affected individuals have just two such symptoms, while maximally affected individuals have 11. Many people equate opioid abuse and addiction with the intake of heroin or other illicit/illegal street narcotics. However, opioid use disorder stemming from the consumption of opioid medications is a far more common phenomenon. Some of the people diagnosed with the disorder use prescription opioids in a purely recreational context. However, significant numbers of people impacted by opioid use disorder are seeking (in a misguided way) to manage their ongoing pain symptoms.
What Are Doctors’ Challenges?
In the study review published in Drug and Alcohol Dependence, researchers from the University of Massachusetts and the University of Pennsylvania explored the challenges that doctors face when trying to address serious, ongoing pain in people clearly affected by opioid use disorder. They chose their area of inquiry, in part, in response to the complex and potentially contradictory needs of individuals dealing with a combination of chronic pain and abuse/addiction associated with the substances often used to treat such pain.
One of the problems identified by the researchers is hyperalgesia. Doctors use this term to describe an unusually heightened level of pain sensitivity that can appear in people who regularly receive opioid medications as a chronic pain treatment. The researchers concluded that people affected by opioid use disorder may undergo chemical and structural changes in their brains that make them more likely to develop hyperalgesia than other long-term prescription opioid users.
The researchers also concluded that medical science has only a partial understanding of the mental and physical factors that contribute to ongoing pain, as well as only a partial understanding of the mental and physical factors that contribute to the onset of addiction. Practically speaking, this means that doctors attempting to balance the needs of pain management with the treatment needs of opioid use disorder have an incomplete picture of their patients’ situations and therefore may not know how to proceed effectively in at least some circumstances.
The review’s authors believe that future research on the complex problems associated with co-existing chronic pain and opioid use disorder must include a search for biomarkers that could help doctors and researchers determine which patients will respond best to which potential treatments. Biomarkers are substances that appear in the bodies of people affected by certain types of disease or other health problems.