20-Year Ongoing Study Looks at Pain in Methadone Users

Researchers from the University of British Columbia since 1995 have been assessing opioid-dependent patients with pain who are on methadone maintenance treatment.

Prescribing opioids as well as determining dependency in patients is not black and white. A study presented at the 34th Annual American Pain Society Scientific Meeting in Palm Springs, CA addresses trends over the years.

Vancouver’s warmer weather is tied to the homeless population which contributes to drug rates. The University of British Columbia has been assessing opioid-dependent patients with pain on methadone maintenance treatment (MMT) since 1995. First author Pauline Voon, BScN, RN, and her colleagues interviewed participants between December 2011 and November 2014 for the latest installment.

“There have been huge fluctuations,” Voon told MD Magazine. “There’s such a huge opioid abuse problem.” Out of the 823 patients, 338 (40.9%) reported having moderate pain while another 91 (11.1%) claimed to have severe pain.

“People on methadone who had high pain severity thought their dosage was too low,” Voon said. The explanation for this is not clear, however, could be caused by two scenarios. Patients may be undertreated for pain or their long-term use of opioids makes them less sensitive to the analgesic effects.

The study revealed that higher pain severity was also associated with self-managing pain, perception of methadone, older age, physical disability, mental illness, and marijuana use.

“It is concerning that MMT patients with higher pain severity were more likely to self-manage pain, given the high-risk methods in which people who use illicit drugs often self-manage pain,” the authors wrote.

Not only has there been a rise in users over the past 2 decades, but the substance on the rise has varied as well.

“Heroin was the drug of choice, and then crystal meth had a phase,” Voon explained. “And now it’s prescription drugs. That’s definitely new.”

As opioid abuse continues to be prevalent, the authors suggested future areas of research including patient education and clinical intervention in order to address patients who self-manage pain.