[Note: Duloxetine (trade name Cymbalta) and pregabalin (trade name Lyrica) are both FDA approved as therapies for symptoms of Fibromyalgia.]
This study assessed the prevalence of comorbidities and/or use of selected medications that may contraindicate the use of duloxetine (DLX and/or pregabalin (PGB) among patients with fibromyalgia (FM).
Using the Pharmetrics Patient-Centric Database, we identified all patients, aged 18 years or older, with 1 or more medical claims with an ICD-9-CM diagnosis code of FM (729.1) between 7/1/2004 and ending 6/30/2005, and at least one such claim in each of the 2 preceding 12-month periods.
We then assessed the prevalence of comorbidities and medication use that could contraindicate DLX and/or PGB.
• Comorbidities (DLX: narrow angle glaucoma, hepatic insufficiency, pregnancy, severe renal impairment, hypertension; PGB: severe renal impairment, hemodialysis, angioedema),
• And medications (DLX: monoamine oxidase inhibitors, serotonergic drugs, inhibitors of CYP1A2 or 2D6, drugs metabolized by CYP2D6, phenothiazines, linezolid; PGB: ACE inhibitors, thiazolidinediones)
… were designated of concern based on product labeling and summary reviews.
A comorbidity of interest was established for 2 or more outpatient claims on different days or any inpatient claims with a relevant ICD-9-CM diagnosis code; medication use was established by any pharmacy claims for the medication.
A total of 33,176 patients with FM were identified in the study database; mean (plus/minus SD) age was 45.5 plus/minus 10.2 years, and 74.5% were women.
In patients taking DLX, 32% had comorbidities and/or used medications that might render DLX use inappropriate – predominantly hypertension (17.2%), prescriptions for CYP1A2 or CYP2D6 inhibitors (13.6%), or for serotonergic drugs (11.5%).
The corresponding figure for PGB was 8% – predominantly ACE inhibitor use (5.9%) or pregnancy (1.6%).
FM patients were four times as likely to have comorbidities and/or to have used other medications that might render them potentially inappropriate candidates for DLX in comparison with PGB. (Supported by Pfizer Inc.)
Source: American Pain Society Annual Scientific Meeting, May 7-9, 2009, Poster #274. Sadosky A, Berger A, Zlateva G, Oster G. Pfizer Global Outcomes Research, New York.