AUSTIN, TX—Comprehensive assessment of patients with fibromyalgia involves more than a physical examination. Treatment of fibromyalgia requires a multidimensional approach that addresses patient symptoms, as well as psychosocial, behavioral, and physical factors, a panel of experts said at the American Pain Society’s 30th Annual Scientific Meeting.
Central nervous system factors such as diffuse hyperalgesia and deficient descending analgesia have been shown to play a major role in fibromyalgia, and are present in subsets of patients with concomitant pain states such as rheumatoid arthritis, systemic lupus erythematosus, low back pain, and osteoarthritis. Thus, Daniel J. Clauw, MD, states “all chronic pain states may be ‘mixed’ pain states with varying contributions from peripheral and central mechanisms in different patients.” Recent research supports a dual-focused strategy that utilizes pharmacotherapy to treat the symptoms of pain and fatigue caused by nerve damage or dysfunction, nociceptive input, and disordered sensory processing, as well as non-pharmacological therapy to address the functional consequences of fibromyalgia symptoms (eg, increased distress, decreased activity, isolation, sleeping disorders).
Treatments approved by the FDA for fibromyalgia are alpha-2-delta ligands (pregabalin) and serotonin and norepinephrine reuptake inhibitors (SNRIs; duloxetine and milnacipran). Lesley M. Arnold, MD, presented results from a clinical study she conducted that demonstrated pregabalin 300mg/day, 450mg/day, and 600mg/day to have significantly reduced fibromyalgia pain one week following initiation of therapy continuing through the end of the trial at Week 14, and improved sleep quality at one week (P<0.05; except for pregabalin 300mg/day at Week 11). Additionally patients reported significant improvement in their Patient Impression of Change (PGIC) assessment (P≤0.05) for all dosages vs. placebo.
Dr. Arnold also evaluated the efficacy of duloxetine 60–120mg/day for fibromyalgia and observed significant improvement of patients’ Brief Pain Inventory (BPI) scores over a 24-hour period (P<0.001). Looking beyond the symptoms of pain, duloxetine improved patient scores for the Multidimensional Fatigue Inventory (MFI) and Beck Depression Index (BDI) (P≤0.007 for both) and PGIC (P<0.001) compared with placebo and shows comparable efficacy in BPI and PGIC scores in patients with or without major depressive disorder.
In a study performed by Dr. Clauw, milnacipran 100mg/day and 200mg/day showed significant improvement in pain beginning at Week 1 through the end of the trial at Week 15 (P<0.01). When evaluating milnacipran’s effect on MFI, BDI, and PGIC, data demonstrated a greater reduction in general fatigue and depression (P≤0.036 for both) and overall improvement (P<0.001). A recent study has looked at combination pharmacological therapy for fibromyalgia and has evaluated add-on milnacipran to pregabalin in patients with incomplete response to pregabalin monotherapy. Results, thus far, have shown a significantly higher percentage of PGIC responders and greater reductions in mean weekly pain recall visual analog scale scores with combination therapy.
Dr. Arnold concludes that clinicians must “identify the important symptom domains, their severity, and level of patient function to guide medication selection.” Pregabalin may be the optimal choice for patients presenting with pain, sleep disturbances and anxiety; whereas the SNRIs may be more effective in patients with pain, fatigue, and depressed mood. Most patients will require a multimodal approach utilizing both drug treatment and non-pharmacological therapy to achieve optimal outcomes.