To assess the efficacy of 4% topical lidocaine in
spheno-palatine blocks, a randomized controlled trial was
carried out on patients with chronic muscle pain syndromes.
Sixty-one patients (42 with fibromyalgia (FM) and 19 with
myofascial pain syndrome (MPS)) completed the trial. Outcome
measures included pain intensity, a daily pain diary, headache
frequency, sensitivity to pressure using a dolorimeter,
anxiety, depression, and sleep quality. Patients were
randomized to receive either 4% lidocaine or sterile water
(placebo) 6 times over a 3-week period. Both subjects and
investigators were blind to treatment allocation.
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The resultsshowed that 4% lidocaine had no superiority over
placebo in any of the outcome measures. Twenty-one subjects
(35%) showed a decrease in pain which was greater than 30%
of their baseline value. Of these 21 subjects, 10 received
lidocaine and 11 received placebo. These data suggest that, in
this population, 4% lidocaine is no better than placebo in the
treatment of chronic muscle pain.
Scudds RA, Janzen V, Delaney G, Heck C, McCain GA, Russell AL,
Teasell RW, Varkey G, Woodbury MG