New research suggests that the abuse potential of opioid analgesics should be explored in pain patients rather than in “recreational users,” as specified in the FDA’s “Guidance for Industry: Assessment of Abuse Potential of Drugs.”
“Abuse potential in recreational users is important information,” Dr. Alfieri and his colleagues indicated in their findings. “However, opioids are labeled for the treatment of pain.
Therefore, understanding the abuse potential among chronic pain patients who are not recreational opioid users (target population) would advance pain treatment.”
The initial results of a study in pain patients receiving a modified form of the questionnaire intended for recreational drug users were presented by Tom Alfieri, PhD, director of Medical Affairs Strategic Research at Purdue Pharma, at PAINWeek 2016
There is a likelihood of introducing bias, according to Dr. Alfieri, when the questionnaire on subjective drug effects intended for recreational drug users is applied to pain patients requiring analgesia.
“For example, evidence of abuse potential may exist when a group of recreational users indicates that they would be ‘very likely’ to take a drug again. However, when a group of pain patients indicates that they would be ‘very likely’ to take a drug again, the liking may be attributed to pain relief, and not necessarily to hedonistic or abuse purposes,” Dr. Alfieri said.
Modifying Measures of Abuse Potential
In following the FDA guidance for studying drug formulations with abuse potential, the investigators recruited recreational drug users to respond on visual analog scales to three key questions: “How high do you feel?” “Do you like this drug?” “How much would you like to take this drug again?”
Dr. Alfieri and his colleagues modified the question on drug liking for pain patients with the qualifiers:
- “My liking for this drug due to pain relief is … ,” and
- “excluding pain relief, my liking for this drug is. …”
The questions on likelihood of repeating drug use were clarified with,
- “I would take this drug again for pain relief,” and
- “excluding pain relief, I would take this drug again.”
The researchers reported that the pain patients clearly understood what “high” means, and that they considered the qualifiers, “for pain relief” and “excluding pain relief,” to be helpful in accurately responding to questions about “drug liking” and “desire to take again.”
The investigators anticipate that the modified questionnaire will be useful in studies of abuse potential in nonrecreational users to avoid confounding pain relief effects with euphoria and other nontherapeutic or hedonic effects
“We are following FDA guidance for PRO [patient-reported outcome] development.
The next round of cognitive debriefing will assess additional modifications we are proposing to the wording of the items,” Dr. Alfieri told Pain Medicine News, “and by administering the items to a larger sample, we are helping to ensure generalizability of the results.”
the study was notable in questioning “the leap of faith [that] the recreational user is, in fact, a valid surrogate for the chronic pain patient.”
researchers should carefully examine all instruments designed for abusers when they are applied to pain patients.
Results from the target population of pain patients should be applied instead, he said, “so that we can get real-world information and more reliable insight.”