Editor's comment: There are currently three drugs that have received FDA approval for the treatment of fibromyalgia (brand names: Lyrica, Cymbalta and Savella). Each one has roughly a 30% success rate for improving FM symptoms. Therefore, when one medication is not helping a patient, it is not unusual for the treating physician to switch the patient to one of the other approved drugs. The purpose of this study was to assess the results of switching fibromyalgia patients who were not being helped by duloxotine (Cymbalta) to milnacipran (Savella). The researchers sought to answer two primary questions: (1) Would patients experience any improvements in pain or other symptoms after switching medications? (2) Can patients be switched from one medication to the other without first tapering down the dosage of the first medication?
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Results of switching to milnacipran in fibromyalgia patients with an inadequate response to duloxetine: a phase IV pilot study
By Lucinda Bateman, et al.
BACKGROUND: The purpose of this study was to evaluate the safety, tolerability, and efficacy of milnacipran following a direct switch from duloxetine in fibromyalgia patients experiencing inadequate clinical response to duloxetine after receiving treatment for 6 weeks or longer.
METHODS: This exploratory study included 107 patients with fibromyalgia who had been treated with duloxetine 60 mg/day for at least 4 weeks prior to enrollment. Following a 2-week open-label period on duloxetine, patients who had visual analog scale pain scores ≥ 40 and were dissatisfied with current treatment were randomized 4:1 to milnacipran 100 mg/day (n = 86) or placebo (n = 21) for 10 weeks of double-blind treatment. The small placebo group was included solely to blind the study and minimize expectation bias among patients and investigators, and there was no preplanned statistical comparison between treatment groups.
The primary efficacy parameter was the percentage of patients rating themselves as "much improved" or "very much improved" on the Patient Global Impression of Change (PGIC) at the final visit. Other efficacy parameters included changes in one-week recall visual analog scale pain, Fibromyalgia Impact Questionnaire Revised (FIQR), and Multiple Ability Self-Report Questionnaire (MASQ).
RESULTS: Of patients switched to milnacipran, 32.9% were classified as PGIC responders, and they also demonstrated improvement in visual analog scale pain, FIQR total, and MASQ total scores (mean changes from baseline were -12.3, -7.77, and -2.39, respectively).
Nausea and dizziness were the most common treatment-emergent adverse events in patients switched to milnacipran, reported in 21% and 15%, respectively, of patients in this group.
CONCLUSION: Results from this exploratory study suggest that switching from duloxetine to milnacipran may be beneficial in some patients with fibromyalgia who have an inadequate response to duloxetine. Further research investigating the efficacy and safety of switching fibromyalgia therapies is warranted.
Source: Journal of Pain Research, April 26, 2013. By Lucinda Bateman, Robert H Palmer, Joel M Trugman, and Yuhua Lin. Fatigue Consultation Clinic, Salt Lake City, UT.