title: Repeated tender point injections of granisetron alleviate chronic myofascial pain--a randomized, controlled, double-blinded trial.
abstract: BACKGROUND
  Serotonin (5-HT) mediates pain by peripheral 5-HT3-receptors. Results from a few studies indicate that intramuscular injections of 5-HT3-antagonists may reduce musculoskeletal pain. The aim of this study was to investigate if repeated intramuscular tender-point injections of the 5-HT3-antagonist granisetron alleviate pain in patients with myofascial temporomandibular disorders (M-TMD).
  
  
  METHODS
  This prospective, randomized, controlled, double blind, parallel-arm trial (RCT) was carried out during at two centers in Stockholm, Sweden. The randomization was performed by a researcher who did not participate in data collection with an internet-based application ( www.randomization.com ). 40 patients with a diagnose of M-TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were randomized to receive repeated injections, one week apart, with either granisetron (GRA; 3 mg) or isotonic saline as control (CTR).
  
  
  RESULTS
  The median weekly pain intensities decreased significantly at all follow-ups (1-, 2-, 6-months) in the GRA-group (Friedman test; P < 0.05), but not in the CTR-group (Friedman-test; P > 0.075). The numbers needed to treat (NNT) were 4 at the 1- and 6-month follow-ups, and 3.3 at the 2-month follow-up in favor of granisetron.
  
  
  CONCLUSIONS
  Repeated intramuscular tender-point injections with granisetron provide a new pharmacological treatment possibility for myofascial pain patients with repeated intramuscular tender-point injections with the serotonin type 3 antagonist granisetron. It showed a clinically relevant pain reducing effect in the temporomandibular region, both in a short- and long-term aspect.
  
  
  BACKGROUND
  European Clinical Trials Database 2005-006042-41 as well as at Clinical Trials NCT02230371 .
authors.affiliation: Department of Dental Medicine, Section for Orofacial Pain and Jaw Function, Karolinska Institutet, and the Scandinavian Center for Orofacial Neurosciences (SCON), Box 4064, Huddinge, SE-141 04, Sweden. Nikolaos.christidis@ki.se.|Department of Clinical Oral Physiology at the Eastman Institute, Stockholm Public Dental Health, Dalagatan 11, Stockholm, SE-113 24, Sweden. Nikolaos.christidis@ki.se.
authors.forename: Nikolaos
authors.identifier: http://orcid.org/0000-0002-8199-7863
authors.initials: N
authors.lastname: Christidis
authors.affiliation: Department of Clinical Oral Physiology at the Eastman Institute, Stockholm Public Dental Health, Dalagatan 11, Stockholm, SE-113 24, Sweden. shahin.omrani@ftv.sll.se.
authors.forename: Shahin
authors.initials: S
authors.lastname: Omrani
authors.affiliation: Department of Clinical Oral Physiology at the Eastman Institute, Stockholm Public Dental Health, Dalagatan 11, Stockholm, SE-113 24, Sweden. lars.fredriksson@ftv.sll.se.
authors.forename: Lars
authors.initials: L
authors.lastname: Fredriksson
authors.affiliation: Department of Dental Medicine, Section for Orofacial Pain and Jaw Function, Karolinska Institutet, and the Scandinavian Center for Orofacial Neurosciences (SCON), Box 4064, Huddinge, SE-141 04, Sweden. mattias.gjelset@stud.ki.se.
authors.forename: Mattias
authors.initials: M
authors.lastname: Gjelset
authors.affiliation: Department of Dental Medicine, Section for Orofacial Pain and Jaw Function, Karolinska Institutet, and the Scandinavian Center for Orofacial Neurosciences (SCON), Box 4064, Huddinge, SE-141 04, Sweden. sofia.louca@ki.se.
authors.forename: Sofia
authors.initials: S
authors.lastname: Louca
authors.affiliation: Department of Clinical Oral Physiology at the Eastman Institute, Stockholm Public Dental Health, Dalagatan 11, Stockholm, SE-113 24, Sweden. britt.hedenberg-magnusson@ftv.sll.se.
authors.forename: Britt
authors.initials: B
authors.lastname: Hedenberg-Magnusson
authors.affiliation: Department of Dental Medicine, Section for Orofacial Pain and Jaw Function, Karolinska Institutet, and the Scandinavian Center for Orofacial Neurosciences (SCON), Box 4064, Huddinge, SE-141 04, Sweden. malin.ernberg@ki.se.
authors.forename: Malin
authors.initials: M
authors.lastname: Ernberg
mesh_terms: D000328:Adult; D059350:Chronic Pain / Q000175:diagnosis* / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D017829:Granisetron / Q000008:administration & dosage*; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000175:diagnosis / Q000188:drug therapy; D009209:Myofascial Pain Syndromes / Q000175:diagnosis* / Q000188:drug therapy*; D010147:Pain Measurement / Q000379:methods; D011446:Prospective Studies; D012702:Serotonin Antagonists / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D017829:Granisetron; D012702:Serotonin Antagonists
keywords: 5-HT3-receptor; Granisetron; Human; Myofascial pain; Temporomandibular disorders