Prescription opioid use in the United States has reached epidemic proportions, with sales nearly quadrupling over the last decade despite an unchanged prevalence of pain.1-3
The epidemic carries a price — more than 140,000 Americans have died from prescription opioid overdose since 1999, and the estimated cost to society is in excess of $50 billion per year.4-6
In an effort to address the issue, the US Food and Drug Administration has published a comprehensive review and action plan,7, 8 while the Centers for Disease Control and Prevention has provided guidelines for opioid use in managing chronic noncancer pain.9
Although these measures are valid, truly curbing opioid misuse requires an understanding of the triggers involved — and a growing body of evidence suggests that craving is a an important factor.
Craving is known to be influenced by patient-specific variables such as sex, negative affect, and history of substance use disorder (SUD),10-13 but few studies have examined the impact of day-to-day changes in pain intensity.
Available data suggest a weak association, with daily pain variations responsible for less than 5% of opioid craving, according to a study published in the March issue of Drug and Alcohol Dependence.14
The finding may be explained by a number of factors, according to lead author Marc O. Martel, PhD, from the department of anesthesiology and pain medicine at Harvard Medical School in Boston, MA.
“Many patients with chronic pain do experience high levels of psychological distress — this might contribute to opioid craving to a greater extent than pain symptoms. Given that the basic properties of opioids may, in some patients, contribute to alleviating psychological distress, those with high levels of psychological distress may be particularly likely to crave their opioid medications, and to overuse them,” Dr Martel told Clinical Pain Advisor.
“There are also a number of genetic and neurobiological factors that might contribute to opioid craving to a greater extent than pain symptoms, but these factors will need to be elucidated through further research,” Dr Martel added.
The definition and interpretation of intensity and duration of chronic pain vary significantly, as reflected by the wide variation in reported US prevalence, which ranges from 11% to 47% and higher.15-18
Still, the majority of Americans prescribed opioids for noncancer chronic pain do not experience euphoria or craving.10 Given that only 3% to 16% of Americans have SUD, it is conceivable that opioid craving affects a significant minority of patients, but studies are needed to confirm this hypothesis.19
Clearly establishing cause and effect between pain intensity and craving is fraught with challenges and study limitations that have been clearly articulated by authors in various studies to date.10-14 These limitations may also contribute to the weak association between pain intensity and opioid craving.