Peripheral KV7 Activation for Pain Relief

Summary

The goal of this clinical trial is to learn if the drug Flupirtine can safely lower pain when used in tiny amounts directly in the skin. The study will test whether Flupirtine works by activating specific nerve channels in the skin called KV7 potassium channels. These channels help control how pain signals travel to the brain.

The main questions the study aims to answer are:

* Does Flupirtine lower pain caused by capsaicin, the active ingredient in chili peppers?
* Does Flupirtine lower pain caused by heat?

Researchers will compare Flupirtine to a placebo (a look-alike injection that does not contain any drug) to see if Flupirtine lowers pain better than the placebo.

Participants will:

* Receive tiny skin injections that contain either Flupirtine, capsaicin, heat, or placebo
* Rate their pain on a scale from 0 (no pain) to 100 (worst pain imaginable)
* Complete all study procedures during one visit that lasts about 1 hour

Only a small amount of Flupirtine will be used in this study-less than 1/800 of the usual dose. The drug is injected into the skin, not taken by mouth. Because of this, the risk of side effects is extremely low.

This study includes healthy adults between the ages of 18 and 70. It does not include people who are pregnant, taking medications, or who have skin or nerve problems.

The goal is to find out if Flupirtine can be used in the future to treat pain in a new way-by working directly in the skin and not in the brain. This could help avoid side effects like tiredness or dizziness.

The study is sponsored by the Medical University of Vienna and follows all safety and ethical rules.

Conditions

• Pain

Interventions

DRUG

Capsaicin only (7.6 ng)

Intradermal injection of 7.6 ng capsaicin (0.5 µM, 50 µL) in synthetic interstitial fluid (SIF) without Flupirtine. Used to induce experimental burning pain in the skin.

DRUG

Capsaicin + Flupirtine 0.5 µg

Intradermal co-injection of 7.6 ng capsaicin (0.5 µM) and 0.5 µg Flupirtine in 50 µL SIF. Used to assess local analgesic effect of very low-dose Flupirtine on chemically induced pain.

DRUG

Capsaicin + Flupirtine 1.2 µg

Intradermal co-injection of 7.6 ng capsaicin and 1.2 µg Flupirtine in 50 µL SIF. Part of dose-response evaluation for peripheral pain inhibition.

DRUG

Capsaicin + Flupirtine 3.0 µg

Intradermal co-injection of 7.6 ng capsaicin and 3.0 µg Flupirtine in 50 µL SIF. Intermediate dose in microdose titration series.

DRUG

Capsaicin + Flupirtine 7.6 µg

Intradermal co-injection of 7.6 ng capsaicin and 7.6 µg Flupirtine in 50 µL SIF. This is the highest Flupirtine microdose used in the capsaicin model.

DRUG

Placebo (SIF only, no capsaicin or Flupirtine)

Intradermal injection of 50 µL synthetic interstitial fluid without capsaicin or Flupirtine. Used as negative control for capsaicin-Flupirtine co-injection conditions.

DRUG

Room Temperature Injection (Control)

Intradermal slow infusion of SIF at \~23°C using a programmable pump. No capsaicin or Flupirtine included. Used as baseline control in heat model.

DRUG

Heated injection without Flupirtine

Intradermal slow infusion of synthetic interstitial fluid preheated up to \~52°C. No Flupirtine included. Used to induce thermal pain in human skin.

DRUG

Heated Injection with Flupirtine 124 µg

Intradermal slow infusion of synthetic interstitial fluid up to \~52°C containing 124 µg Flupirtine. Used to test local analgesic effect of high-dose Flupirtine in heat pain model.

Sponsors & Collaborators

• Stefan Heber

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Model

CROSSOVER

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2025-05-08

Primary Completion

2025-05-28

Completion

2025-05-28

Countries

• Austria

Study Locations