The Influence of Tramadol on Platelet Function

Study Overview
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Brief Summary
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The aim of this ex-vivo study is to quantify the effect of tramadol on platelet aggregation.

Detailed Description
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The aim of this study is to quantify the effect of tramadol on platelet aggregation. To this end, the effect of tramadol on platelet function will be demonstrated in an ex-vivo study using optical aggregometry (LTA) on whole blood of 15 patients. The main objective variable is to use platelet function assays (LTA) as well as thrombelastography (TEG) to determine this effect on platelet function. The null hypothesis of this study is that tramadol does not affect platelet aggregation in healthy patients. In addition, two further questions will be addressed: using a titration series, to attempt to plot a dose/response curve of the effect of tramadol on platelet function. tramadol is often administered together with other drugs such as NSAIDs (ibuprofen), novalgin, SSRIs or other opioids such as morphine or in the surgical setting fentanyl and remifentanil. A series of studies will be conducted to determine whether these combinations alter the effect of tramadol on platelet function.

Official Title
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The Influence of Tramadol on Platelet Function

Conditions
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Drug Toxicity, Platelet Dysfunction, Clotting Disorder

Intervention / Treatment
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* Drug: Tramadol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18y and older, healthy volunteers Exclusion Criteria: Age < 18 years Pregnant women History of addiction (especially opiate abuse) Pre-existing general addictive disease Ongoing pain therapy with opiates Taking antidepressants (SNRI, SSRI) History of thrombocytopathy or coagulation disorders Therapy with drugs that influence thrombocyte function (ASS, clopidogrel, prasugrel, ticagrelor or similar) Known intolerance to opiates

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: procoagulant effect on platelet function<br>LTA platelet function measurement on whole blood with addition of tramadol, demonstration of a dose-response relationship and determination of the effect of combination with other drugs. | Drug: Tramadol<br>* Blood samples will be drawn from 15 patients. Tramadol will be added to all this samples in-vitro and its influence on platelets´ function will be measured.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Procoagulant effect on platelet function demonstrated by optical aggregometry (LTA) on whole blood. | The effect of tramadol on platelet function will be demonstrated in an ex-vivo study using optical aggregometry (LTA) on whole blood of 15 patients. The study team expects a noticeable procoagulant effect due to the increase in serotonin in the synaptic cleft in the LTA platelet function measurement by ADP, both in AUC and graphically represented as a curve. | up to 4 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dose/ Response - Curve | The study team will use a titration series, to attempt to plot a dose/response curve of the effect of tramadol on platelets´ function. This question is examined on half of the blood samples (7). | up to 4 hours | 
| Combinations with Tramadol and other drugs and their procoagulant effect on platelet function demonstrated by optical aggregometry (LTA) on whole blood. | Tramadol is often administered together with other drugs such as NSAIDs (ibuprofen), novalgin, SSRIs or other opioids such as morphine or in the surgical setting fentanyl and remifentanil. A series of studies will be conducted to determine whether these combinations alter the effect of tramadol on platelet function. This question will be examined on the other half of the whole blood samples (7) and measured in the LTA platelet function measurement by ADP, both in AUC and graphically represented as a curve. | up to 4 hours |