Local treatment of tendinopathies and myofascial pain syndromes with the 5-HT3 receptor antagonist tropisetron.
The use of local tropisetron injections improved the treatment of tendinopathies considerably, with the effect being comparable to the topical application of local anaesthetics combined with depot corticosteroids. On the other hand, local injection of prilocaine alone exerted a shorter and weaker effect on the condition.


OBJECTIVE
After it had been proven that systemic application of the 5-HT3 receptor antagonist tropisetron exerts an analgesic effect on musculoskeletal pain in fibromyalgia, we investigated the efficacy of the substance in tendinopathies and myofascial pain syndromes.


RESULTS
Local injections of tropisetron as a treatment for trigger points in myofascial pain syndrome also brought about rapid and prolonged relief in the majority of cases. The analgesic effect was far superior to the action of local anaesthetics.


CONCLUSIONS
The present findings indicate that the analgesic action of the 5-HT3 receptor antagonist tropisetron sets in rapidly and lasts for a long time. Various mechanisms are under discussion to explain the long duration of the effect. Tropisetron not only has an analgesic but probably also an antiphlogistic effect which can be attributed to the inhibited release of substance P and other neuropeptides from the nociceptors and the blocked release of phlogistic substances from macrophages, monocytes etc.
Müller
W
W
Hochrhein Institute of Rehabilitation Research, Bad Säckingen, Germany. mehrer@hri.de
Stratz
T
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007211:Indoles / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009135:Muscular Diseases / Q000188:drug therapy; D009209:Myofascial Pain Syndromes / Q000188:drug therapy*; D058831:Serotonin 5-HT3 Receptor Antagonists; D012702:Serotonin Antagonists / Q000627:therapeutic use*; D013710:Tendons; D013997:Time Factors; D000077526:Tropisetron
D000779:Anesthetics, Local; D007211:Indoles; D058831:Serotonin 5-HT3 Receptor Antagonists; D012702:Serotonin Antagonists; D000077526:Tropisetron