Tropisetron

Overview

Tropisetron is a non-peptide small-molecule indole-tropane carboxylate ester with dual receptor activity: competitive antagonism at 5-HT3 serotonin receptors and partial agonism at α7 nicotinic acetylcholine receptors. Approved in 1992 as a prescription antiemetic (marketed as Navoban outside the United States) for chemotherapy- and radiotherapy-induced nausea and vomiting, it is NOT approved or marketed in the US. Beyond its approved indication, tropisetron has registered human RCT data in fibromyalgia and schizophrenia-associated cognitive deficits; NO validated human dosing exists for cognitive enhancement in healthy individuals. Available from gray-market research-chemical vendors labeled for laboratory research only.

Mechanism of Action

Tropisetron acts as a selective competitive antagonist at 5-HT3 serotonin receptors, the basis of its approved antiemetic use. It also functions as a partial agonist at α7 nicotinic acetylcholine receptors, demonstrated in Xenopus oocytes expressing human α7/α4β2/α3β4 nAChR and rat 5-HT3A receptors, with the tropane moiety identified as the minimal α7 pharmacophore. A separate study reported that low-nanomolar tropisetron (10–30 nM) sensitizes α7 and α7β2 currents to submaximal acetylcholine rather than acting as a conventional orthosteric agonist at those concentrations.

Research Summary

Tropisetron is an approved prescription drug for chemotherapy-/radiotherapy-induced nausea and vomiting. Human RCT data exist for two investigational uses: (a) a randomized, double-blind, placebo-controlled multicenter trial in 418 fibromyalgia patients (5/10/15 mg once daily × 10 days) reported a higher responder rate in the 5 mg arm than placebo; and (b) an 8-week randomized, double-blind, placebo-controlled trial in 40 risperidone-treated schizophrenia patients (10 mg/day add-on) improved P50 auditory gating and sustained visual attention versus placebo. NO validated human dosing exists for cognitive enhancement in healthy individuals. Preclinical findings include: in vitro (Xenopus oocytes) confirmation of α7-selective partial agonism; in vivo (young/aged rats, aged rhesus monkeys) improvements in novel-object-recognition and delayed-match-to-sample accuracy with systemic tropisetron; rat 3-nitropropionic-acid Huntington's model showing improved motor/behavioral deficits and modulation of Nrf2/HO-1, PI3K/Akt, and JAK2/NF-κB signaling; and rat pilocarpine temporal-lobe-epilepsy model demonstrating reduced spontaneous seizures and hippocampal sclerosis via an α7nAChR-dependent (alpha-bungarotoxin-reversible) mechanism.

Vendors selling Tropisetron

Scored vendors carrying Tropisetron, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Reported Side Effects

• Headache
• Constipation
• Transient diarrhea
• Dizziness
• Dry mouth

Compare Tropisetron with Others

Research References

• PubChem Compound Summary for CID 656665, Tropisetron.
• Molecular dissection of tropisetron, an alpha7 nicotinic acetylcholine receptor-selective partial agonist. 2005. PMID 15781147.
• Pharmacokinetics of therapeutic doses of tropisetron in healthy volunteers. 2001. PMID 11736884.
• Short-term treatment of primary fibromyalgia with the 5-HT3-receptor antagonist tropisetron: randomized, double-blind, placebo-controlled multicenter trial in 418 patients (Int J Clin Pharmacol Res 2001 — journal corrected from source dossier). 2001. PMID 11708570.

Frequently asked questions

Has Tropisetron been independently lab-tested?

Disclosed Labs has collected 1 Certificate of Analysis (COA) for Tropisetron from 1 independent testing lab. 1 vendor has submitted material for testing. Products average 99.8% tested purity across the corpus. Full testing data is available at https://www.disclosedlabs.com/peptides/tropisetron/testing.

Where can researchers source Tropisetron?

1 vendor with Disclosed Labs trust grades currently list Tropisetron, including Kimera Chems. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/tropisetron.

How does Tropisetron work?

Tropisetron acts as a selective competitive antagonist at 5-HT3 serotonin receptors, the basis of its approved antiemetic use. It also functions as a partial agonist at α7 nicotinic acetylcholine receptors, demonstrated in Xenopus oocytes expressing human α7/α4β2/α3β4 nAChR and rat 5-HT3A receptors, with the tropane moiety identified as the minimal α7 pharmacophore. A separate study reported that low-nanomolar tropisetron (10–30 nM) sensitizes α7 and α7β2 currents to submaximal acetylcholine rather than acting as a conventional orthosteric agonist at those concentrations.

What does the research say about Tropisetron?

Tropisetron is an approved prescription drug for chemotherapy-/radiotherapy-induced nausea and vomiting. Human RCT data exist for two investigational uses: (a) a randomized, double-blind, placebo-controlled multicenter trial in 418 fibromyalgia patients (5/10/15 mg once daily × 10 days) reported a higher responder rate in the 5 mg arm than placebo; and (b) an 8-week randomized, double-blind, placebo-controlled trial in 40 risperidone-treated schizophrenia patients (10 mg/day add-on) improved P50 auditory gating and sustained visual attention versus placebo. NO validated human dosing exists for cognitive enhancement in healthy individuals. Preclinical findings include: in vitro (Xenopus oocytes) confirmation of α7-selective partial agonism; in vivo (young/aged rats, aged rhesus monkeys) improvements in novel-object-recognition and delayed-match-to-sample accuracy with systemic tropisetron; rat 3-nitropropionic-acid Huntington's model showing improved motor/behavioral deficits and modulation of Nrf2/HO-1, PI3K/Akt, and JAK2/NF-κB signaling; and rat pilocarpine temporal-lobe-epilepsy model demonstrating reduced spontaneous seizures and hippocampal sclerosis via an α7nAChR-dependent (alpha-bungarotoxin-reversible) mechanism.