NCT01862523

Mechanisms of Capsaicin Treatment in Idiopathic Rhinitis Patients and Controls

Unraveling the Mechanisms of Capsaicin Treatment in Idiopathic Rhinitis Patients and Controls by Measuring Mucosal Potentials in the Nose.

• Status: Completed
• Phase: Phase 4
• Study type: Interventional
• Enrollment: 39 (actual)
• Sponsor: Universitaire Ziekenhuizen KU Leuven · Academic / Other
• Sex: All
• Age: 18 Years – 60 Years
• Healthy volunteers: Accepted

Summary

Capsaicin nasal spray is used in daily practice against IR without knowledge about the exact mechanisms involved in this treatment. Therefore, this study aims to address this issue by studying the functional (electrophysiologic) changes after specific stimulations in IR patients and healthy controls before and after capsaicin/placebo treatment.

Detailed description

As an essential step towards the improvement of the treatment of IR we will investigate the neural mechanisms underlying the therapeutic action of capsaicin. In particular, we plan to evaluate the effects of capsaicin on the functional properties of the innervation of nasal mucosa by monitoring the trigeminal nerve activity using measurements of negative mucosa potentials (NMP). NMPs, will be evoked by chemical and thermal stimuli in IR patients and healthy controls. Considering the evidence suggesting a role of sensory C-fibers in the pathophysiology of IR, we will employ low concentrations of irritants that specifically activate receptors expressed in those fibers, i.e., capsaicin for TRPV1 and cinnamaldehyde and allyl-isothiocyanate (mustard oil) for TRPA1. The same stimulations will be performed immediately after capsaicin treatment, and after 4 weeks, 3 months and 6 months. This will allow for an objective assessment of the functionality of the C-fiber innervation before the treatment, during the phase of therapeutic response and during the period of recurrence of the IR symptoms. The results of the NMP measurements will be contrasted with the therapeutic response and with evaluations of nasal congestion, nasal sensitivity and the presence of neuro-mediators found in nasal biopsies. Importantly, the independent assessment of the NMP responses mediated by either TRPV1 or TRPA1 will allow determining the specific role of these nociceptors in the pathophysiology of IR, which, in turn, may help to design more specific and effective therapies.

Conditions

• Rhinitis

Interventions

Type	Name	Description
BIOLOGICAL	Capsaicin	Thirty-three\* well-characterized IR patients will be recruited and screened for participation in this study with nasal capsaicin spray (0,1 mmol/l ) using the treatment regimen described by van Rijswijk et al. (1 x 5 applications in one day, with 1 hour between each application)
BIOLOGICAL	diluent	diluent

Timeline

• Start date: 2012-02-01
• Primary completion: 2014-12-01
• Completion: 2014-12-01
• First posted: 2013-05-24
• Last updated: 2014-12-05

Locations

1 site across 1 country: Belgium