Efficacy and tolerability of tropisetron in primary fibromyalgia--a highly selective and competitive 5-HT3 receptor antagonist. German Fibromyalgia Study Group.

Abstract

OBJECTIVE:

Based on a potential role for serotonin receptors in fibromyalgia, we investigated the efficacy and tolerability of treatment with tropisetron, a highly selective, competitive inhibitor of the 5-HT3 receptor.

METHODS:

In this prospective, multicenter, double-blind, parallel-group, dose-finding study, 418 patients suffering from primary fibromyalgia (ACR criteria) were randomly assigned to receive either placebo, 5 mg, 10 mg or 15 mg tropisetron once daily, respectively. The duration of treatment was 10 days. The clinical response was measured by changes in pain-score, visual analog scale (VAS), and the number of painful tender-points.

RESULTS:

Treatment with 5 mg tropisetron resulted in a significantly higher response rate (39.2%) when compared with placebo (26.2%) (p=0.033). The absolute reduction in pain-score was -13.5% for 5 mg tropisetron, -13.0% for 10 mg tropisetron, and -6.3% for placebo (p<0.05). The effects of 15 mg tropisetron were similar to placebo, thus suggesting a bell-shaped dose-response curve. Compared with placebo, treatment with 5 mg tropisetron led to a significant improvement (p<0.05) in VAS, while a clear trend in terms of clinical benefit was seen with 10 mg tropisetron. The number of painful tender-points was also reduced significantly (p=0.002) in the 5 mg tropisetron group. Of interest, during the 12-month follow-up period, pain intensity of responders on 5 mg and 10 mg tropisetron was still markedly below baseline. The treatment was well tolerated, with gastro-intestinal complaints being the most frequently reported side effects, in keeping with the known safety profile for 5-HT3 receptor antagonists.

CONCLUSIONS:

This study demonstrates the efficacy of short-term treatment with 5 mg tropisetron once daily in primary fibromyalgia. Treatment was well tolerated and prolonged clinical benefits were seen.

• Authors: L Färber, T Stratz, W Brückle, M Späth, D Pongratz, J Lautenschläger, I Kötter, B Zöller, H H Peter, G Neeck, R Alten, W Müller
• Journal: Scandinavian journal of rheumatology. Supplement (Scand J Rheumatol Suppl) Vol. 113 Pg. 49-54 ( 2000) ISSN: 0301-3847 [Print] Norway
• PMID: 11028832 (Publication Type: Clinical Trial, Comparative Study, Journal Article, Multicenter Study, Randomized Controlled Trial)

Chemical References

• Indoles
• Placebos
• Receptors, Serotonin
• Receptors, Serotonin, 5-HT3
• Serotonin Antagonists
• Tropisetron

Topics

• Adolescent
• Adult
• Aged
• Double-Blind Method
• Female
• Fibromyalgia (drug therapy, physiopathology)
• Follow-Up Studies
• Humans
• Indoles (adverse effects, therapeutic use)
• Male
• Middle Aged
• Pain Measurement
• Placebos
• Prospective Studies
• Receptors, Serotonin (drug effects, physiology)
• Receptors, Serotonin, 5-HT3
• Serotonin Antagonists (adverse effects, therapeutic use)
• Tropisetron