A. Berger1, G. Oster1, T. Juday2, M. H. Erder2, S. Blum*2
1Research, Policy Analysis Inc., Brookline, 2Health Outcomes, Forest Research Institute, Jersey City, United States

Background: Opioids are not typically recommended for the treatment of fibromyalgia (FM), due to their limited efficacy in this indication and risk of addiction and/or abuse. Little is known about the extent to which these agents are used in this patient population.
Objectives: To document patterns of use of opioids in FM patients in the US.
Methods: Using a large US health insurance database spanning a three-year period (1/1/2005 to 12/31/2007), we identified all patients with ≥1 medical encounters for FM (defined as ICD-9-CM code 729.1) in each of these three calendar years (“FM patients”). We documented the percentage of patients receiving opioids (including both short- and long-acting formulations) as well as the number of prescriptions for--and therapy-days with--such agents in each of the three years. Prescriptions and therapy-days were annualized to account for differences in days of enrollment in each year.
Results: A total of 51,885 patients met all study entry criteria, of whom 37.2%, 38.9%, and 38.9% filled ≥1 prescriptions for opioids in 2005, 2006, and 2007, respectively. Most patients received short-acting opioids (36.4%, 37.9%, and 37.9%), although 7.2%, 8.6%, and 9.1% received long-acting formulations. The most commonly used short-acting opioids were hydrocodone (~24% annually), followed by oxycodone (~11% annually), and tramadol (~10%); the most commonly used long-acting opioids were oxycodone (~3%), fentanyl (~3%), and morphine (~2%). On an annualized basis, FM patients who received opioids averaged 8.0 (95% confidence interval = 7.9, 8.1) prescriptions for such therapy constituting 158.6 (155.6, 161.6) therapy-days in 2005; corresponding values were 8.5 (8.4, 8.7) and 178.9 (175.8, 182.1) for 2006 and 8.3 (8.2, 8.5) and 181.4 (178.2, 184.6) in 2007. FM patients who received opioids also often received other FM-related therapies, including antidepressants (used by ~63% of such patients annually), followed by sedatives/hypnotics (~33%), and antiepileptics and antidepressants (~28%).

Conclusion: Despite a lack of demonstrated efficacy in this disease and their potential for addiction and abuse, opioids are used by more than one-third of FM patients. Further research is needed to understand why the use of these agents in clinical practice is so high.

Disclosure of Interest: A. Berger, Forest Research Institute, ConsultantG. Oster, Forest Research Institute, ConsultantT. Juday, Forest Research Institute, EmployeeS. Blum, Forest Research Institute, EmployeeM.H. Erder, Forest Research Institute, Employee