AnalgesiaNCT00970450
The Central Analgesic Effects of Paracetamol on Serotonergic Pathways
A study testing Paracetamol and Tropisetron in people with Analgesia, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
Trial summary
1. Introduction Paracetamol, an analgesic prescribed daily, has been in use for more than 50 years. Surprisingly, its mode of action is still unclear. One postulated mechanism is the reinforcement of descending inhibitory pathways. Read more about this study
- Who is it for?
- Ages 20 to 35 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Analgesia
- What is being tested?
- Paracetamol and Tropisetron
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 16 participants
- Where
- 1 siteSwitzerland
- Study dates
- Nov 2009to Apr 2010
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 35 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy male volunteers
- 20-35 years of age
- No known medical disorders
- BMI 18.5 - 39.9 (kg/m2)
Who cannot join
- Known drug allergies (paracetamol, tropisetron)
- Excessive consumption of tobacco (more than 10 cigarettes a day)
- Excessive consumption of tea or coffee (more than 5 cups a day)
- Recreational drug addiction
- Consumption of any medication on the trial days
Trial locations and contacts
1 site in 1 country.
About this study
- Introduction Paracetamol, an analgesic prescribed daily, has been in use for more than 50 years. Surprisingly, its mode of action is still unclear. One postulated mechanism is the reinforcement of descending inhibitory pathways. A recent publication in a human pain model raises the question of whether or not Paracetamol acts according to a central serotonergic mechanism. Unfortunately, the chosen model was unable to differentiate between overall pain, secondary hyperalgesia and allodynia. In particular, secondary hyperalgesia and allodynia are central effects. The planned study will examine the central analgesic effects of paracetamol on allodynia and hyperalgesia by blocking the central effect by adding tropisetron. It will be based on an internationally accepted model for the initiation of secondary hyperalgesia, which was developed and tested by colleagues in Erlangen.
- Study work plan This prospective, randomized, placebo-controlled, double-blinded, cross-over trial in 16 male volunteers will address pain ratings and the area of secondary hyperalgesia/allodynia in a human model of electrically evoked pain and compare four different treatment scenarios:
- Paracetamol 1 g;
- Paracetamol, 1 g and Tropisetron 5 mg;
- Tropisetron, 5 mg; and
- Saline. Each volunteer will be allocated to each scenario in a cross-over fashion. Four separate treatment trials, at least two weeks apart, will be performed. Each volunteer will be familiarized with the stimulation procedure prior to participation.
Read more
- Ethical considerations Informed consent will be obtained from each volunteer. In addition, each volunteer will receive remuneration after participating in the study. Paracetamol is considered to be a very safe drug in healthy patients. Tropisetron, another safe medication, is routinely used in anaesthetic practice as an antiemetic drug. Headache, flush and liver parameter elevation are very rare side effects of minor importance in our daily clinical work as anaesthetists. This pain provoking procedure was developed at the University Erlangen Germany. It is a standardized method and has repeatedly received approval by research ethics committees internationally. Furthermore, the investigators applied this model to a recent study in Basel (cf your decision "study protocol 330/07;" unpublished data, analysis and writing in progress).
- Patient number and timetable The investigators will examine 16 volunteers and expect the experimental component to last 3 months. The investigators plan to complete this study within one year.
- Study importance
The mode of action of paracetamol remains unclear. The investigators think that this study will enable them to answer important questions concerning the action of paracetamol. The investigators hope that further understanding of this regularly prescribed drug will help us to better understand the complex mechanisms of pain.
- Conditions
- Analgesia
- Being tested
- Paracetamol, Tropisetron, Placebo
- Keywords
- Paracetamol, Tropisetron, Central analgesic effect, Area of allodynia, Secondary hyperalgesia
- Medical subject headings
- Agnosia, Hyperalgesia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ParacetamolDrug
Paracetamol 1 g i.v. once
TropisetronDrug
Tropisetron 5 mg i.v. once
PlaceboDrug
Saline
| Study group | Role | What they receive |
|---|---|---|
| Paracetamol | Experimental | Not described Receives: Drug: Paracetamol |
| Paracetamol/Tropisetron | Experimental | Not described Receives: Drug: Paracetamol; Drug: Tropisetron |
| Saline | Placebo comparator | Proband will receive Saline Receives: Drug: Placebo |
| Tropisetron | Active comparator | Proband will receive Tropisetron alone Receives: Drug: Tropisetron |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pain
Measured: all 20 minutes up to 180 minutes after starting the experiment
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Sep 2009 (estimated)
- Study startNov 2009
- Primary completionMar 2010
- Study completionApr 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AnalgesiaStudies of the same condition, open and under way.
- More trials run by University Hospital, Basel, SwitzerlandThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 16 participants (actual)
Sponsor and investigators
- Lead sponsor
- University Hospital, Basel, Switzerland
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Wilhelm Ruppen, MD, Principal investigator, University Hospital, Basel, Switzerland
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00970450
- Sponsor's protocol ID
- DAAnaBaselParacetamol 2
- Status last verified
- Jan 2013
- First submitted
- 20 Aug 2009
- Last updated
- 29 Jan 2013
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 29 Jan 2013. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Central Analgesic Effects of Paracetamol on Serotonergic Pathways
- ClinicalTrials.gov ID
- NCT00970450
- Acronym / sponsor ID
- DAAnaBaselParacetamol 2
- Conditions
- Analgesia
- Keywords
- Paracetamol, Tropisetron, Central analgesic effect, Area of allodynia, Secondary hyperalgesia
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 16 participants (actual)
- Lead sponsor
- University Hospital, Basel, SwitzerlandUniversity, hospital or other
- Study start
- Nov 2009
- Primary completion
- Mar 2010 (actual)
- Study completion
- Apr 2010 (actual)
- First posted
- 2 Sep 2009 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
- Introduction Paracetamol, an analgesic prescribed daily, has been in use for more than 50 years. Surprisingly, its mode of action is still unclear. One postulated mechanism is the reinforcement of descending inhibitory pathways. A recent publication in a human pain model raises the question of whether or not Paracetamol acts according to a central serotonergic mechanism. Unfortunately, the chosen model was unable to differentiate between overall pain, secondary hyperalgesia and allodynia. In particular, secondary hyperalgesia and allodynia are central effects. The planned study will examine the central analgesic effects of paracetamol on allodynia and hyperalgesia by blocking the central effect by adding tropisetron. It will be based on an internationally accepted model for the initiation of secondary hyperalgesia, which was developed and tested by colleagues in Erlangen.
- Study work plan This prospective, randomized, placebo-controlled, double-blinded, cross-over trial in 16 male volunteers will address pain ratings and the area of secondary hyperalgesia/allodynia in a human model of electrically evoked pain and compare four different treatment scenarios:
- Paracetamol 1 g;
- Paracetamol, 1 g and Tropisetron 5 mg;
- Tropisetron, 5 mg; and
- Saline. Each volunteer will be allocated to each scenario in a cross-over fashion. Four separate treatment trials, at least two weeks apart, will be performed. Each volunteer will be familiarized with the stimulation procedure prior to participation.
- Ethical considerations Informed consent will be obtained from each volunteer. In addition, each volunteer will receive remuneration after participating in the study. Paracetamol is considered to be a very safe drug in healthy patients. Tropisetron, another safe medication, is routinely used in anaesthetic practice as an antiemetic drug. Headache, flush and liver parameter elevation are very rare side effects of minor importance in our daily clinical work as anaesthetists. This pain provoking procedure was developed at the University Erlangen Germany. It is a standardized method and has repeatedly received approval by research ethics committees internationally. Furthermore, the investigators applied this model to a recent study in Basel (cf your decision "study protocol 330/07;" unpublished data, analysis and writing in progress).
- Patient number and timetable The investigators will examine 16 volunteers and expect the experimental component to last 3 months. The investigators plan to complete this study within one year.
- Study importance
The mode of action of paracetamol remains unclear. The investigators think that this study will enable them to answer important questions concerning the action of paracetamol. The investigators hope that further understanding of this regularly prescribed drug will help us to better understand the complex mechanisms of pain.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, care provider)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Paracetamol | Experimental | Drug: Paracetamol |
| Paracetamol/Tropisetron | Experimental | Drug: Paracetamol, Drug: Tropisetron |
| Saline | Placebo comparator | Drug: PlaceboProband will receive Saline |
| Tropisetron | Active comparator | Drug: TropisetronProband will receive Tropisetron alone |
Who may qualify
- Ages
- 20 to 35 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Healthy male volunteers
- 20-35 years of age
- No known medical disorders
- BMI 18.5 - 39.9 (kg/m2)
Key exclusion criteria (5 listed)
- Known drug allergies (paracetamol, tropisetron)
- Excessive consumption of tobacco (more than 10 cigarettes a day)
- Excessive consumption of tea or coffee (more than 5 cups a day)
- Recreational drug addiction
- Consumption of any medication on the trial days
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ParacetamolParacetamol 1 g i.v. once | Drug | Paracetamol, Paracetamol/Tropisetron |
| TropisetronTropisetron 5 mg i.v. once | Drug | Paracetamol/Tropisetron, Tropisetron |
| PlaceboSaline | Drug | Saline |
Primary outcome
Pain
Time frame: all 20 minutes up to 180 minutes after starting the experiment
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 29 Jan 2013.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Wilhelm Ruppen, MD principal investigator
University Hospital, Basel, Switzerland
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Paracetamol and Tropisetron in people with Analgesia, run by University Hospital, Basel, Switzerland at 1 site in Switzerland.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 29 Jan 2013. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Switzerland. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pain (time frame: all 20 minutes up to 180 minutes after starting the experiment). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Jan 2013.