Determination of the Antidepressant Duloxetine in Plasma to Improve the Knowledge of the Analgesic Action of Antidepressants on Chronic Neuropathic Pain

Study Overview
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Brief Summary
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The primary purpose of this protocol is to evaluate the lowest plasma concentration (ie before the daily taking dose of duloxetine) in patients relieved of at least 30% of their neuropathic pain with duloxetine treatment. The secondary purpose of this protocol is to determine plasmatic concentration peak (ie 6 hours after taking duloxetine) in patients relieved of at least 30% of their neuropathic pain with duloxetine treatment. Others secondary purposes are to evaluate the intensity of neuropathic pain, to assess the degree of pain relief and to evaluate the sensation of the global improvement experienced by the patient.

Official Title
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DULOPLASM Study: Pilot Study on Mechanisms of Analgesic Action of Duloxetine: Effective Dosage of Duloxetine at the Peak and at the Lowest Plasma Concentrations

Conditions
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Neuropathic Pain

Intervention / Treatment
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* Drug: duloxetine


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: aged 40 to 75 years old relieved of their neuropathic pain by 60 mg of duloxetine treatment (with a differential of> 30% in the intensity of neuropathic pain with NRS, before and after treatment initiation) Exclusion criteria: concomitant treatment with enoxacin, fluvoxamine, flecainide, propafenone, metoprolol, risperidone, verapamil, omeprazole, modafinil, mequitazine, propafenone, tamoxifen, Monoamine Oxidase Inhibitors.

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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 |
| --- | --- |
| Other: patient treated by duloxetine<br> | Drug: duloxetine<br>* The concentration of duloxetine is measured by liquid chromatography coupled to tandem mass spectrometry on blood sample<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measurement of the lowest plasma concentration of duloxetine in pmol/mL. |  | The concentration of duloxetine is measured by liquid chromatography coupled to tandem mass spectrometry on blood sample taken at the inclusion visit (V0), before the daily morning dose of duloxetine. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Measurement of the plasma concentration peak of duloxetine in pmol/mL. |  | The concentration of duloxetine is measured by liquid chromatography coupled to tandem mass spectrometry on blood sample taken during the V1 visit (28 days after V0, 6 hours after the daily morning dose of duloxetine). | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Neuropathic pain, Antidepressant, Duloxetine, Liquid Chromatography, Mass Spectrometry