T Stratz1, B Fiebich, U Haus, W Müller. 1. Hochrhein Institute of Rehabilitation Research, Department of Clinical Research, Bad Säckingen, Germany.
Abstract
BACKGROUND: Substance P is found at an elevated level in the cerebrospinal fluid of fibromyalgia (FM) patients. Treatment with tropisetron leads in a subgroup of FM patients to pain reduction. The question arises of whether the substance P level in the serum can be changed by tropisetron treatment. METHOD: Twenty patients with FM diagnosed according to the ACR criteria were treated for 5 days with a 5 mg tropisetron intravenous (i.v.) bolus injection daily. Before the first injection, 3 h later, and before and 3 h after the last injection, the serum levels of substance P were determined. The determination of this substance was carried out by means of an immunoassay from Assay Design Biotrend, Cologne. To evaluate the success of the tropisetron treatment, patients made a global assessment as 'clearly better', 'better', 'unchanged', or 'poor'. Patients who answered 'clearly better' and 'better' were regarded as responders. RESULTS: Of the 20 patients, ten reported a good or very good influence on their pain (responders). In these responders, the means of the serum substance P levels were elevated in comparison with the non-responders, though the difference was not significant. In responders, the 5-HT3 receptor antagonist tropisetron produced a significant decrease in the serum substance P levels, while this did not occur in the non-responders. CONCLUSION: It is possible that the responders to tropisetron represent a subgroup of FM patients for whom substance P and 5-HT3 receptors play key roles in the development of the pain symptoms.
BACKGROUND:Substance P is found at an elevated level in the cerebrospinal fluid of fibromyalgia (FM) patients. Treatment with tropisetron leads in a subgroup of FM patients to pain reduction. The question arises of whether the substance P level in the serum can be changed by tropisetron treatment. METHOD: Twenty patients with FM diagnosed according to the ACR criteria were treated for 5 days with a 5 mg tropisetron intravenous (i.v.) bolus injection daily. Before the first injection, 3 h later, and before and 3 h after the last injection, the serum levels of substance P were determined. The determination of this substance was carried out by means of an immunoassay from Assay Design Biotrend, Cologne. To evaluate the success of the tropisetron treatment, patients made a global assessment as 'clearly better', 'better', 'unchanged', or 'poor'. Patients who answered 'clearly better' and 'better' were regarded as responders. RESULTS: Of the 20 patients, ten reported a good or very good influence on their pain (responders). In these responders, the means of the serum substance P levels were elevated in comparison with the non-responders, though the difference was not significant. In responders, the 5-HT3 receptor antagonist tropisetron produced a significant decrease in the serum substance P levels, while this did not occur in the non-responders. CONCLUSION: It is possible that the responders to tropisetron represent a subgroup of FM patients for whom substance P and 5-HT3 receptors play key roles in the development of the pain symptoms.
Authors: Laura Bazzichi; Gino Giannaccini; Laura Betti; Giovanni Mascia; Laura Fabbrini; Paola Italiani; Francesca De Feo; Tiziana Giuliano; Camillo Giacomelli; Alessandra Rossi; Antonio Lucacchini; Stefano Bombardieri Journal: Arthritis Res Ther Date: 2006 Impact factor: 5.156