Clinical characteristics, pharmacotherapy, and healthcare resource use among patients with fibromyalgia newly prescribed pregabalin or tricyclic antidepressants

Objective: To examine treatment patterns and costs among patients with fibromyalgia prescribed pregabalin or tricyclic antidepressants (TCAs). Methods: Using the LifeLink™ Health Plan Claims Database, patients with fibromyalgia (International Classification of Diseases, Ninth Revision, Clinical Modification code 729.1X) newly prescribed (index date) TCAs (n=898) were identified and propensity score-matched (PSM) with patients newly prescribed pregabalin (n=898). Pain-related pharmacotherapy, comorbidities, and healthcare resource use/costs were examined during the 12 months, pre-index, and follow-up periods. Results: Both patient groups reported multiple comorbidities and received pain medications in the pre-index and follow-up periods. Among patients prescribed pregabalin, use of non-selective non-steroidal anti-inflammatory drugs (43.3% vs 39.8%), other anticonvulsants (28.6% vs 23.3%), and tetracyclic/miscellaneous antidepressants (28.5% vs 25.8%) significantly decreased, and cyclooxygenase 2 (COX-2) inhibitors (7.7% vs 10.4%), TCAs (4.8% vs 7.9%), and topical agents (10.8% vs 15.1%) increased in the follow-up period (p<0.05). Among patients prescribed TCAs, there were significant decreases in muscle relaxants (42.0% vs 38.4%) and sedative hypnotics (27.4% vs 23.9%), and increases in COX-2 inhibitors (5.8% vs 7.9%) and anticonvulsants (25.1% vs 33.7%; p<0.05). There were increases (p<0.0001) in pharmacy costs in both cohorts and total healthcare costs in the pregabalin cohort from pre-index to follow-up. Median total costs were higher (p<0.05) in the pregabalin group vs TCAs in the pre-index ($$9935 vs $$8771) and follow-up ($$10,689 vs $$8379) periods. Limitations: Despite attempts to address bias through PSM, the higher pre-index costs in the pregabalin cohort suggest a channeling of patients with more severe fibromyalgia to pregabalin. Conclusions: Patients with fibromyalgia prescribed pregabalin or TCAs had multiple comorbidities and a sizeable pain medication burden, which increased in the follow-up period for both cohorts. Only 5% of pregabalin initiators had been treated with concomitant TCAs at baseline, suggesting that TCAs were inappropriate for these patients owing to their contraindications.