Clinical characteristics and medication uses among fibromyalgia patients newly prescribed amitriptyline, duloxetine, gabapentin or pregabalin.
By S.C. Kim, J.E. Landon and D.H. Solomon.
Background: Fibromyalgia is a common chronic pain disorder with unclear etiology. No definitive treatment is available for fibromyalgia and treatment with antidepressants or antiepileptics is often used for symptom management.
Methods: Using US health care utilization data, a large population-based cohort study was conducted to describe clinical characteristics and medication use patterns in patients diagnosed with fibromyalgia who newly started amitriptyline, duloxetine, gabapentin or pregabalin.
Results: There were 13,404 amitriptyline, 18,420 duloxetine, 23,268 gabapentin, and 19,286 pregabalin starters. The mean age ranged from 48 to 51 years and 72% to 84% were women in each group.
Back pain was the most frequent comorbidity in all four groups (48%-64%) and hypertension, headache, depression, and sleep disorder were also common.
Median daily dose at the start of follow-up was 25mg for amitriptyline, 60mg for duloxetine, 300mg for gabapentin, and 75mg for pregabalin and more than 60% of patients remained on the same dose throughout the follow-up period.
Only one fifth of patients continued the treatment started for at least one year.
The mean number of different prescription drugs at baseline ranged from 8 to 10 across the groups.
More than a half of patients used opioids and a third used benzodiazepines, sleep disorder drugs and muscle relaxants.
Conclusion: Patients who started one of the four common drugs for fibromyalgia similarly had multiple comorbidities and other fibromyalgia-related drug use, but continued the treatment only for a short time. The dose of the four drugs was not increased in most patients during the follow-up.
© 2013 American College of Rheumatology.
Source: Arthritis Care & Research, July 16, 2013. By S.C. Kim, J.E. Landon and D.H. Solomon. Division of Pharmacoepidemiology and Pharmacoeconomics, Brigham and Women's Hospital, Boston, MA; Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital.