title: Botulinum toxin A versus bupivacaine trigger point injections for the treatment of myofascial pain syndrome: a randomised double blind crossover study.
abstract: The treatment of myofascial pain syndrome (MPS) is diverse and includes trigger point injections of various substances including local anesthetics, steroids and Botulinum toxin A (BTX A). The purpose of this study was to compare the effectiveness of trigger point injections using BTX A versus bupivacaine, both in combination with a home-based rehabilitation program. To be enrolled, subjects first had to demonstrate responsiveness to bupivacaine trigger point injection. In this single center, double blind, randomized, cross-over trial, 18 patients with MPS received trigger point injections of either 25 units Botulinum toxin A or 0.5 ml of 0.5% bupivacaine per trigger point. A maximum of eight trigger points were injected per subject. Subjects were followed until their pain returned to 75% or more of their pre-injection pain for two consecutive weeks, after which there was a 2 week wash-out period. The subjects then crossed over and had the same trigger points injected with the other agent. All subjects participated in a home exercise program involving static stretches of the affected muscles. Both treatments were effective in reducing pain when compared to baseline (P=0.0067). There was, however, no significant difference between the BTX A and 0.5% bupivacaine groups in duration or magnitude of pain relief, function, satisfaction or cost of care (cost of injectate excluded). Considering the high cost of BTX A, bupivacaine is deemed a more cost-effective injectate for MPS.
authors.affiliation: Glenrose Rehabilitation Hospital, 10230 111Ave, Edmonton Ab, T5G 0B7, Canada. cgraboski@shaw.ca
authors.forename: Corrie L
authors.initials: CL
authors.lastname: Graboski
authors.forename: D Shaun
authors.initials: DS
authors.lastname: Gray
authors.forename: Robert S
authors.initials: RS
authors.lastname: Burnham
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D019274:Botulinum Toxins, Type A / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D002045:Bupivacaine / Q000008:administration & dosage / Q000191:economics / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D016527:Drug Costs; D005157:Facial Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D017048:Health Care Costs; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects / Q000503:physiopathology; D010147:Pain Measurement; D010808:Physical Examination; D010810:Physical and Rehabilitation Medicine / Q000379:methods; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D019274:Botulinum Toxins, Type A; D002045:Bupivacaine