Naltrexone and Fibromyalgia

Today a survey on the net attracted my attention. Fibromyalgia patients rated different therapies. Have a look at the survey: “What Patients Say Works for Fibromyalgia” (link below). I don’t think that medication is solving the problem, but I wouldn’t apodictically say no to effective treatments. Not to my surprise you see a very low effectiveness of drugs like savella, Prozac, Cymbalta, gabapentin, and Lyrica according to the ratings. But the rating of naltrexone surprised me.

Younger has published one naltrexone in fibromyalgia: 2009 a pilot study and recently a longer study. I had voiced some concerns in 2009 on this blog.
Let’s have a closer look at the newer study of J. Younger and colleagues: “Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing daily pain levels.” In results we find: “When contrasting the condition end points, we observed a significantly greater reduction of baseline pain in those taking low-dose naltrexone than in those taking placebo (28.8% reduction versus 18.0% reduction; P = 0.016).” That’s the same level as in pregabalin/Lyrica. I can only look at the abstract, so I don’t know if the primary endpoint has been changed or not. The primary outcome measure was set at 30% reduction of symptoms over placebo. The level of pain reduction in the Crofford study had been set at a reduction of 50%. So it seems that naltrexone isn’t even as effective as Lyrica. And I’ve already voiced my concerns about the effectiveness of Lyrica in treating fibromyalgia. In conclusions the authors write: “The preliminary evidence continues to show that low-dose naltrexone has a specific and clinically beneficial impact on fibromyalgia pain. […] Parallel-group randomized controlled trials are needed to fully determine the efficacy of the medication.” Let’s wait for these results. Until then I rate this study as one that does more benefit to the drug company than to patients. I’m ready to change my point of view, if new evidence surfaces, but I’m very sceptical that I have to.

Links:
Survey: http://blog.23andme.com/23andme-research/what-patients-say-works-for-fibromyalgia/  
Younger study 2009: http://www.ncbi.nlm.nih.gov/pubmed/19453963  
Younger study 2013: http://www.ncbi.nlm.nih.gov/pubmed/23359310  
Pregabalin and Fibromyalgia: http://rheumatologe.blogspot.de/2012/06/fibromyalgia-and-pregabalin-some-ideas.html