title: Influence of intramuscular granisetron on experimentally induced muscle pain by acidic saline.
abstract: The aim of this study was to investigate whether intramuscular administration of the 5-HT(3) receptor antagonist granisetron reduces experimental muscle pain induced by repeated intramuscular injections of acidic saline into the masseter muscles. Twenty-eight healthy and pain-free volunteers, fourteen women and fourteen men participated in this randomized, double-blind and placebo-controlled study. After a screening examination and registration of the baseline pressure-pain threshold (PPT), the first simultaneous bilateral injections of 0·5 mL acidic saline (9 mg mL(-1) , pH 3·3) into the masseter muscles were performed. Two days later, PPT and pain (VAS) were re-assessed. The masseter muscle was then pre-treated with 0·5 mL granisetron (Kytril(®) 1 mg mL(-1) pH 5·3) on one side and control substance (isotonic saline, 9 mg mL(-1) pH 6) on the contralateral side. Two minutes thereafter a bilateral simultaneous injection of 0·5 mL acidic saline followed. The evoked pain intensity, pain duration, pain area and PPT were assessed. The volunteers returned 1 week later to re-assess VAS and PPT. On the side pre-treated with granisetron, the induced pain had significantly lower intensity and shorter duration (P < 0·05) compared with the side pre-treated with control. A subgroup analysis showed that the effect of granisetron on pain duration was significant only in women (P < 0·001), while the effect on peak pain and pain area were significant in both sexes. The results showed no significant change in PPT. In conclusion, these results indicate that granisetron has a pain-reducing effect on experimentally induced muscle pain by repeated acidic saline injection.
authors.affiliation: Section for Orofacial Pain and Jaw Function, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden. sofia.louca@ki.se
authors.forename: S
authors.initials: S
authors.lastname: Louca
authors.forename: M
authors.initials: M
authors.lastname: Ernberg
authors.forename: N
authors.initials: N
authors.lastname: Christidis
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D017829:Granisetron / Q000627:therapeutic use*; D006801:Humans; D007273:Injections, Intramuscular; D008297:Male; D008406:Masseter Muscle / Q000187:drug effects*; D063806:Myalgia / Q000139:chemically induced / Q000188:drug therapy*; D010147:Pain Measurement; D017288:Pain Threshold / Q000187:drug effects*; D012702:Serotonin Antagonists / Q000627:therapeutic use*; D012737:Sex Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D017829:Granisetron; D012702:Serotonin Antagonists