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Study on the Effects of Tetrodotoxin for Pain Relief in Healthy Volunteers

Fast replyInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a medication called Halneuron, which contains the active substance tetrodotoxin. The study is being conducted to understand how this medication affects the body's ability to sense things, particularly in relation to pain. Tetrodotoxin is administered as a solution for injection under the skin, and the trial involves giving healthy volunteers different doses of this medication.

The main purpose of the study is to evaluate how the peripheral nervous system, which is the part of the nervous system outside the brain and spinal cord, responds to the medication. This is done using a method called Quantitative Sensory Testing (QST), which measures how the body senses things like touch, temperature, and pain. The study will look at changes in these sensory measurements after the medication is given.

Participants in the study will receive two different doses of Halneuron and will undergo sensory testing to see how their responses change. The study will also compare the effects of the two doses and monitor any side effects that may occur. The goal is to gather information on how tetrodotoxin affects sensory perception and to ensure its safety for future use in managing pain.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit

    Upon joining the study, you will attend an initial visit where you will receive detailed information about the trial. This includes understanding the purpose, procedures, and any potential risks or benefits.

    You will be asked to sign an informed consent form, confirming your willingness to participate and adhere to the study requirements.

  2. Step 2

    Screening

    During the screening phase, your health will be assessed to ensure you meet the study's eligibility criteria. This includes checking your age, weight, and overall health status.

    Blood pressure, heart rate, and other vital signs will be measured. Blood tests may be conducted to confirm normal kidney function and other health indicators.

  3. Step 3

    Baseline measurements

    Before receiving any medication, baseline measurements will be taken. This involves conducting quantitative sensory testing (QST) to assess your sensory responses.

    Additional tests may include odor identification and threshold tests, as well as a hypoxic ventilatory response test, which measures your breathing response to low oxygen levels.

  4. Step 4

    Medication administration

    You will receive a single dose of Halneuron® (tetrodotoxin for injection) administered subcutaneously, which means it will be injected under the skin.

    The study involves two different doses, and you will be informed about the specific dose you receive.

  5. Step 5

    Post-dose assessments

    One hour after receiving the medication, the same sensory tests conducted at baseline will be repeated to assess any changes in your sensory responses.

    These tests will help evaluate the effect of the medication on your peripheral nervous system.

  6. Step 6

    Monitoring and follow-up

    You will be monitored for any adverse events or side effects following the medication administration. This is to ensure your safety and well-being throughout the trial.

    Follow-up visits may be scheduled to further assess your health and gather additional data as required by the study protocol.

Who can join the trial?

9 criteria

  • Willingness to follow the study rules, shown by signing a valid informed consent form.
  • Generally healthy males and females, aged between 18 and 55 years, with a body mass index (BMI) between 19 and 30 kg/m2. BMI is a measure of body fat based on height and weight.
  • Weigh at least 50 kg.
  • Have normal kidney function, measured by a test called creatinine clearance, which should be between 80 and 180 mL/min.
  • Have blood test results within the normal range. If not, they should be considered not important for health by a study doctor.
  • Have a physical exam that is normal or not important for health according to a study doctor.
  • Have a blood pressure between 100/60 mmHg and 160/100 mmHg and a pulse rate between 50 and 100 beats per minute after resting for 5 minutes. If the first readings are not typical, they can be checked again.
  • Be a nonsmoker or have quit smoking at least 6 months ago.
  • Women who can have children and men must agree to use effective birth control methods, like hormonal or double-barrier methods, or abstain from sex during the study.

Who cannot join the trial?

7 criteria

  • Participants must not have any ongoing **pain** conditions.
  • Participants must not have any known allergies to **Tetrodotoxin (TTX)**, which is a substance used in the study.
  • Participants must not be taking any medications that affect the **nervous system**, which is the network of nerves in the body that sends signals to and from the brain.
  • Participants must not have any history of **neurological disorders**, which are conditions that affect the brain, spinal cord, or nerves.
  • Participants must not be pregnant or breastfeeding.
  • Participants must not have participated in another clinical trial within the last 30 days.
  • Participants must not have any significant medical conditions that could interfere with the study results.
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Investigated drugs

Halneuron is a medication being studied for its effects on the peripheral nervous system. It is administered through an injection under the skin. The purpose of this study is to understand how this medication affects the body's ability to sense things like touch, temperature, and pain. By doing this, researchers hope to learn more about how the medication might be used to help people with certain types of nerve problems in the future.

What is already known about the treatment

Halneuron (Tetrodotoxin (TTX) for Injection) – This medication is administered through an injection under the skin, known as subcutaneous administration. It is currently being studied in clinical trials to understand its effects on the peripheral nervous system, particularly in relation to pain management. The main therapeutic use of Halneuron is to help manage pain by blocking nerve signals. At the molecular level, Tetrodotoxin works by inhibiting sodium channels in nerve cells, which prevents the transmission of pain signals. It is classified pharmacologically as a neurotoxin, specifically targeting nerve function to alleviate pain.

Investigated diseases

Pain – Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. It can be acute, lasting for a short period, or chronic, persisting for weeks, months, or even years. Pain can arise from various sources, including injury, inflammation, or nerve damage. It often serves as a warning signal to the body, indicating that something is wrong. The sensation of pain is processed by the nervous system, which transmits signals from the affected area to the brain. Over time, pain can lead to changes in the nervous system, potentially altering how pain is perceived and experienced.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2022-500318-24-00Estimated enrolment25 patientsSponsorLeids Universitair Medisch Centrum (LUMC)

sourced from the EU Clinical Trials Register and site verification

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