Research suggests treatment of fibromyalgia should be tailored to individual symptoms

High efficacy and acceptability were demonstrated in both on-label and off-label medications for fibromyalgia, reinforcing the value of symptom-based treatment plans, according to a study published in JAMA Network Open.

“Amitriptyline is commonly used off-label for pain relief, fatigue, sleep disturbance, depression and improving [quality of life] for patients with fibromyalgia,” Hussein M. Farag, PharmD, MSc, PhD, of the department of pharmaceutical economics and policy at Massachusetts College of Pharmacy and Health Sciences, and colleagues wrote. “Despite the well-established value of using amitriptyline for fibromyalgia, the off-label policy renders defining the true efficacy and acceptability profile of the drug ambiguous.”

Researchers aimed to assess the comparative effectiveness of amitriptyline along with FDA-approved medications pregabalin, duloxetine and milnacipran for the treatment of fibromyalgia by conducting a systemic review and meta-analysis using PubMed/MEDLINE, the Cochrane Library, Embase and Clinicaltrials.gov data sources.

Their search was conducted on Nov. 20, 2018, and utilized data from 36 randomized clinical trials, which included 11,930 patients (mean age, 48.4 years; 94.4% women), comparing amitriptyline or other FDA-approved doses of drugs approved to treat fibromyalgia. The search was updated on July 29, 2020.

Comparative effectiveness and acceptability were defined as discontinuation of treatment owing to adverse drug reaction associated with off-label amitriptyline, as well as on-label pregabalin (150-mg, 300-mg, 450-mg and 600-mg doses), duloxetine (60 mg and 120 mg), and milnacipran (100 mg and 200 mg) for reducing fibromyalgia symptoms.

Results showed that amitriptyline was associated with reduced sleep disturbances [standard mean differences (SMDs) = 0.97; 95% CI, 1.1 to 0.83], fatigue (SMD = 0.64; 95% CI, 0.75 to 0.53) and improved quality of life (SMD = 0.8; 95% CI, 0.94 to 0.65) compared with placebo. A 120-mg dose of duloxetine was associated with the highest improvement in pain (SMD = 0.33; 95% CI, 0.36 to 0.3) and depression (SMD = 0.25; 95% CI, 0.32 to 0.17) compared with placebo.

In addition, all treatments — except amitriptyline (OR = 0.78; 95% CI, 0.31 to 1.66) — were associated with a higher dropout rate compared with placebo.

“These findings suggest that for optimal health outcomes in patients with fibromyalgia, pharmacological treatments should be tailored toward individual symptoms,” Farag and colleagues wrote.