Real-World Role of Tricyclic Antidepressants in the Treatment of Fibromyalgia

Objective: To examine the real-world role of tricyclic antidepressants (TCAs) in fibromyalgia (FM) treatment. Methods: Using privately insured U.S. administrative claims data, this study examined TCA use for newly diagnosed FM patients. Patients ages 18 to 64 years with = 2 FM diagnoses (ICD-9-CM: 729.1) during Q1:2007 to Q1:2009, no previous FM diagnosis, and continuous eligibility for insurance during the year before and after the first FM diagnosis (study period) were identified as newly diagnosed (N = 10,129). Treatment with TCAs was examined over the first treatment episode (allowing up to a 45-day gap between refills). A sensitivity analysis was performed excluding patients with depression/anxiety diagnoses during the study period. Results: During the study period, 8.9% of patients with FM used TCAs at anytime, 5.0% used TCAs during the year before FM diagnosis, and 7.2% used TCAs during the year after. The mean (median) duration of the first treatment episode was 150 (58) days. During this episode, 84.0% used other medications concomitantly, with 60.3% using analgesics and 39.6% using other antidepressants. Additionally, 60.8% augmented TCA use with other drugs, 61.8% switched to another drug at the end of their TCA episode, and 22.8% discontinued TCAs without switching. Similar patterns were observed for the subset of patients with no depression or anxiety (N = 7,655). Discussion: Research covering 1999 to 2005 using the same methods found that 15.9% of patients with FM used TCAs during the year before FM diagnosis and 20.7% used TCAs during the year after. These findings suggest that TCA use among the patients with FM is uncommon and may be declining in real-world practice.