A treatment of MS-related pain. #MSBlog #MSResearch #ClinicSpeak
“Pain, in particular myelopathic pain from spinal cord involvement, is a massive problem in MS. MSers describe this constant gnawing pain in their backs that affects their ability to function normally. The pain probably arises from lesions affecting the pain pathways in the spinal cord that causes the nerves to fire spontaneously, which results in the brain perceiving the signals as pain. Pain feeds a viscous cycle of negative symptoms, in particular depression, anxiety and fatigue, which make the pain worse. Poor sleep at night due to pain is a major contributor to daytime sleepiness and fatigue. Therefore breaking the cycle is important to improve quality of life. The study below is reassuring and confirms my personal experience that duloxetine can help with this problem. Duloxetine is an anti-depressant that works by reducing the reuptake of serotonin and norepinephrine in the brain; it is referred to as a serotonin and norepinephrine reuptake inhibitor or SNRI. Duloxetine is used to treat depression and anxiety disorders, musculoskeletal pain. and stress urinary incontinence. Neurologists also use it to treat painful peripheral neuropathy, for example neuropathy in people with diabetes. I also use the class of drugs called tricyclic antidepressants for pain. The tricyclics have the advanatge of being more sedating that duloxetine and help MSers get a good nights sleep. Tricyclics have so called anti-cholinergic effects, typically dryness of the mouth and constipation, which can be very troublesome. The message here is that we have treatment options for pain; if you are in pain you need to discuss things with your neurologist and see if any of the options discussed above are suitable for you.”
Epub: Vollmer et al. A Randomized, Double-Blind, Placebo-Controlled Trial of Duloxetine for the Treatment of Pain in Patients with Multiple Sclerosis. Pain Pract. 2013 Oct 24.
BACKGROUND: MSers often report neuropathic pain (NP-MS). The purpose of this study was to assess the efficacy and tolerability of duloxetine as treatment for NP-MS.
METHODS: In this study, 239 adults with NP-MS (duloxetine = 118, placebo = 121) were randomized to duloxetine 60 mg (30 mg for 1 week, then 60 mg for 5 weeks) or placebo once daily for a 6-week acute therapy phase, followed by a 12-week open-label extension phase (duloxetine 30 to 120 mg/day). Eligible MSers had MS for ≥ 1 year and a score ≥ 4 on daily average pain intensity (API) ratings for ≥ 4 of 7 days immediately before randomization. MSers rated API daily on an 11-point numeric scale (0 [no pain] to 10 [worst possible pain]) in an electronic diary. The primary efficacy measure, change in weekly API ratings, was analyzed longitudinally with a mixed-model repeated-measures analysis. Completion, reasons for discontinuation, and treatment-emergent adverse event incidence were compared by Fisher’s exact test.
RESULTS: Duloxetine-treated MSers had statistically greater mean improvement in API vs. placebo at Week 6 (-1.83 vs. -1.07, P = 0.001). Treatment completion did not significantly differ between groups. Discontinuation due to adverse events was statistically greater for duloxetine vs. placebo (13.6% vs. 4.1%, P = 0.012). Decreased appetite was reported significantly more often by duloxetine-treated MSers (5.9% vs. 0%, P = 0.007).
CONCLUSIONS: This study found analgesic efficacy of duloxetine for NP-MS. Duloxetine is not approved for treatment of this condition. The duloxetine safety profile of this study was consistent with the known profile in other patient populations.