Presented at the 2012 AAPM Annual Meeting « Back

Meperidine Adherence and Concomitant Medication Use in Patients with Chronic Pain

Kathleen V. Moy, MS, kamoy@ucsd.edu¹, Rabia S. Atayee, PharmD BCPS², Joseph D. Ma, PharmD³, Brookie M. Best, PharmD MAS⁴, Amadeo J. Pesce, PhD DABCC⁵, (1) UC San Diego Skaggs School of Pharmacy and Pharmaceutical Sciences, San Diego, California, (2) UCSD Skaggs School of Pharmacy, La Jolla, California, (3) Pharmacy, La Jolla, California, (4) UC San Diego, La Jolla, California, (5) Millennium Research Institute, San Diego, California

Introduction: Meperidine (Demerol®) is an opioid prescribed for moderate to severe pain. Meperidine is associated with serious adverse reactions, with an increased risk when it is taken concomitantly with other CNS depressants. Nonadherence and unreported concomitant medications may contribute to unsafe use of meperidine. This study characterizes rate of meperidine adherence and percentage of co-prescribed and detected CNS depressant medications in patients with chronic pain using urinary excretion data. Methods: This was a retrospective analysis on de-identified urine specimens from patients with chronic pain tested at Millennium Laboratories. IRB approval was received from UCSD Human Research Protection Program. Prescription information was taken from physician-reported medication lists. Specimen drug concentrations were quantified using LC-MS/MS between March 2008 and May 2011, and considered positive if concentrations of parent drug or metabolite were above the lower limit of quantitation. Results: 66% of subjects tested positive for meperidine of the total that were prescribed meperidine. 70% of subjects who tested positive for meperidine did not have meperidine reported in their medication lists. 64% had at least one other opioid co-prescribed with meperidine (non-reported use, 2–17%). 47% had at least one benzodiazepine co-prescribed (non-reported use, 32%). Conclusions: This study suggests that non-adherence plays a role in meperidine use. Unreported meperidine use suggests significant non-prescription use and/or use without physician knowledge. In addition, CNS depressants were commonly co-prescribed. Patients should be monitored closely for adherence as well as concomitant medication use.

Funding: An unrestricted grant was given to the UCSD Skaggs School of Pharmacy and Pharmaceutical Sciences to fund the summer internships by Millennium Laboratories, Inc.