Capsaicin Patch 8 % for the Treatment of Persistent Pain After Inguinal Herniotomy

Study Overview
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Brief Summary
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In the present study the investigators intend to investigate analgesic and sensory effects of a capsaicin patch 8 %(Qutenza) in patients with severe post-herniotomy pain and sensory abnormalities in the skin.

Conditions
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Persistent Pain After Inguinal Herniotomy

Intervention / Treatment
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* Drug: capsaicin patch (qutenza)
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients ASA (American Society´s of Anesthesiology´s classification) scores I-III Severe post-herniotomy pain for more than six months and with severe pain (numerical rating scale [NRS] 0-10 points) during rest or during movement > 5. Exclusion Criteria: History of an allergic reaction or intolerance to capsaicin or vehicle ingredients in the patches Severe cardiac impairment, e.g., NYHA (New York Heart Association) Class ≥ III Inflamed or injured skin at the application site Signs of cognitive impairment Known drug or ethanol abuse

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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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: capsaicin patch<br> | Drug: capsaicin patch (qutenza)<br> <br> |
| Placebo Comparator: placebo patch<br> | Drug: Placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain change capsaicin vs. placebo patch treatment | Summed pain intensity (SPI) is calculated as median pain intensities at rest, during transition from the supine lying to the standing erect position, and auto-palpation twice each day for the last 3 days at baseline and at 1 months, 2 months and 3 months during follow-up. The primary outcome measure is the maximum difference between the summed pain intensity differences (SPID) for the phases: Baseline, 1 month, 2 month or 3 month. Δ SPID is then calculated as the difference in SPID between capsaicin and placebo treated patients. | Pain intensity assessed at baseline and at 1,2,3 months follow-up | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in AAS (Activities Assessment Scale) score |  |  | 
| Changes in HADS (Hospital Anxiety and Depression Scale) score |  |  | 
| Changes in QST (Quantitative sensory testing) |  |  | 
| Changes in sleep (Sleep Interference Scale) score |  |  | 
| Changes in S-LANSS (Leeds self-assessment of neuropathic symptoms and signs) |  |  | 
| Changes in intraepidermal nerve fiber density |  |  | 
| Subgroup analysis for pain change(summed pain intensity differences (SPID) capsaicin patch vs. placebo are made for patients with thermal hypoesthesia and thermal normo/hyperesthesia |  |  | 
| Changes in PCS (Pain Catastrophizing Scale) score |  |  |