The Effects Of Tizanidine HCL (Zanaflex®) In Patients With Fibromyalgia

David McLain, MD, Brookwood Medical Center, Birmingham, AL This open‐label, single‐center, dose‐finding study of Zanaflex (tizanidine hydrochloride) in 43 patients diagnosed with fibromyalgia showed some effectiveness in reducing pain and other symptoms of this syndrome. Fibromyalgia is a common syndrome characterized by chronic musculoskeletal pain in all 4 quadrants and pain in 18 identified tender points. Effects on fatigue, pain, sleep, and tender points were assessed before and during treatment. Starting doses of 2 mg/day were increased to 4 mg/day after 5 days and increased further as tolerated. Most patients stayed at 4 mg/day or 8 mg/day, and the highest dosage achieved was 12 mg/day. After the initial visit, 6 patients discontinued Zanaflex because of side effects (headaches in 3, hallucinations in 1, hypotension in 1, asthenia in 1), and 11 did not return for a follow‐up visit. Results are presented for the remaining 26 patients (25 females; average age 50 years (range, 36–64 years); 25 Caucasian, 1 African‐American; 9 on disability or applying for it; all stable on one or more of the following concomitant medications: narcotic analgesics 15%, antidepressants 65%, NSAIDs 46%). On average, at the first follow‐up visit (average time 7.8 weeks), patients showed reduction in tender points and improvement on global assessment (GA) scores, Fibromyalgia Impact Questionnaire (FIQ) results, and visual assessment (VAS) scores for fatigue, pain, and sleep. The results for patients still working or retired were better than those for patients on disability or applying for it. Of the 26 patients in this ongoing study, 14 have had second follow‐up visits (average time 13.3 weeks). Of these, 2 discontinued the drug at the second follow‐up visit. Six of these patients responded especially well to long‐term treatment (average age 51 years; range 46–60 years; 5 females; 1 on disability or applying for it) and showed the following averaged results: global assessment improved by 47%, FIQ by 35%, VAS‐fatigue by 48%, VAS‐pain by 40%, VAS‐sleep by 37%, and tender points by 18%. Zanaflex appears to be effective in improving overall functioning, reducing pain and fatigue, improving sleep, and reducing the number of painful tender points in some patients with fibromyalgia, especially in those who are not on disability or applying for it.