About two-thirds of fibromyalgia patients do not get the starting dose recommended by the FDA in the label it places on an approved medication, a recent study that looked at data collected on thousands of patients over nine years reports.

Currently there are three medications approved by the U.S. Food and Drug Administration (FDA) for the treatment of fibromyalgia: Lyrica (pregabalin), Cymbalta (duloxetine) and Savella (milnacipran).  “Only approximately 34% of patients were prescribed FDA-approved drugs for fibromyalgia at the recommended starting dose,” the researchers wrote.   

Real-world considerations of physicians’ prescribing patterns are behind this practice.  “The appropriate dose of fibromyalgia medications can be individualized to optimize the benefits and reduce side effects,” the researchers said.

The retrospective study, “Analysis of Real-World Dosing Patterns for the 3 FDA-Approved Medications in the Treatment of Fibromyalgia,” was published in the American Health & Drug Benefits. 

In the study, researchers analyzed real-world prescribing patterns and dosing of these medications based on electronic records stored at the IQVIA‘s medical database between January 2006 and December 2014. It examined a total of 1,043 patients treated with Lyrica at a starting dose of 176 mg/day, 1,281 treated with Cymbalta at a starting dose of 56 mg/day, and 326 treated with Savella at a starting dose of 95 mg/day. Mean treatment duration with Cymbalta, Lyrica and Savella was 205, 167 and 167 days, respectively.

Findings revealed that 35% of patients treated with Lyrica were given a starting dose lower than the recommended dosage in the product label. This also happened in the case of patients treated with Cymbalta and Savella, but to a lesser extent (7% and 0.31%, respectively).

In addition, only 27% of the patients treated with Lyrica received the recommended maintenance dose defined in the U.S. prescribing information (USPI). Researchers said this wide variance may be due to Lyrica’s record of effectiveness at lower levels. “Even when patients who received pregabalin were prescribed doses in the recommended maintenance range, we found that the duration of time spent at that recommended maintenance dose was significantly shorter compared with patients who were prescribed duloxetine or milnacipran,” they said.

Conversely, most patients treated with Cymbalta and Savella received the recommended maintenance dose defined in the USPI (91% and 80%, respectively). 

From the three drugs analyzed, Cymbalta was the one that had a higher percentage of patients (15%) exceeding the label-recommended maximum dose. “Approximately 15% of patients receiving doses of ≥100%, and nearly 10% of patients receiving doses between 175% and 200% of the label-recommended maximum dose,” the study noted.  

These findings highlighted the importance of future research into the real-world decision-making of prescribing physicians and why this variance exists. “The reasons for this discordance should be elucidated in future investigations,” it concluded.