NCT00435682

To Study the Peripheral Effect of Botulinum Toxin-A (Botox-A) on Experimentally Induced Cutaneous Pain in Healthy Subjects

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: —
• Sponsor: Aalborg University · Academic / Other
• Sex: Male
• Age: 18 Years – 40 Years
• Healthy volunteers: Accepted

Summary

This is a human trial to study the peripheral effect of therapeutic botulinum toxin (botox-A). The trial is performed on healthy normal males. The study comprises of two parallel placebo-controlled, double blinded studies. In experiment 1 intramuscular Botox will be given in corrugator (one site) and frontalis (two sites) muscles on one side and placebo to the other side. Intradermal (i.d.) capsaicin injection will be given to both sides (between the two sites of frontalis injection horizontally). Capsaicin-induced pain intensity and flare together with the area of hypersensitivity to different stimulus modalities will be measured and mapped at specific time points using different cutaneous stimuli (thermal, electrical, tactile, pressure). This will characterize which fibres and receptors are affected by Botox and will show if Botox have a unilateral effect (peripheral) or if it also affects the contralateral side (central effect). In experiment 2 intradermal Botox will be given in corrugator (one site) and frontalis (two sites) muscles on one side and placebo to the other side. I.d. capsaicin injection will be given to both sides (between the two sites of frontalis injection horizontally). Capsaicin-induced pain intensity and flare together with the area of hypersensitivity to different stimulus modalities will be measured and mapped at specific time points using different cutaneous stimuli (thermal, electrical, tactile, pressure). This will characterize which fibres and receptors are affected by Botox. The effect of intradermal Botox will be compared to the results of experiment 1. The two experiments will show if the intramuscular Botox exerts its action via a leak of Botox from the muscle to the overlying skin. Antipruritic effects of Botox on histamine prick test and itch will also be assessed in parallel with the experiment 2. In this sub-experiment, 5 Units of Botox will be injected intradermally in the middle of volar forearm. The same volume of placebo will be injected into the other side. Histamine prick test will induce itch and the effect of intradermal Botox will be assessed compared to the baseline. Flare area and visual analogue scale (VAS) ratings will be measured.

Conditions

• Healthy

Interventions

Type	Name	Description
DRUG	Botox (Allergan Inc., US)

Timeline

• Start date: 2007-03-01
• Primary completion: 2008-01-01
• Completion: 2008-01-01
• First posted: 2007-02-15
• Last updated: 2008-02-08

Locations

1 site across 1 country: Denmark