Treatment of Chronic Itch in Patients Under Arsenic Exposure With Sublingual Naloxone

Study Overview
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Brief Summary
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The purpose of this study is to assess the efficacy and safety of sublingual naloxone in the treatment of chronic itch in patients under arsenic exposure.

Detailed Description
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This study aims to determine the efficacy and safety of sublingual naloxone in the treatment of chronic, refractory itch in patients under long-term arsenic exposure. In this study, 200 subjects with a moderate-to-severe symptom of itching (numeric rating scale, NRS≥3) will be recruited and randomly treated with either sublingual naloxone (100 subjects) or placebo (100 subjects). The severity of itching will be evaluated in the wash out phase, baseline, and one week after the treatment through reporting of subjective symptomatology (itch NRS) via the interview. Quality of sleep measured by the Pittsburgh Sleep Quality Index (PSQI) and Dermatology Life Quality Index (DLQI) will serve as the secondary outcome.

Official Title
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Treatment of Chronic Itch in Patients Under Arsenic Exposure With Sublingual Naloxone: A Single-blind Randomized Trial

Conditions
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Chronic Pruritus

Intervention / Treatment
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* Drug: Naloxone
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged 18 years or over and without diseases except arsenic-related pruritus Ability to study protocol and to give informed consent by himself/herself voluntarily The number of male or female subjects is required more than 1/3 of the total number of subjects Hair arsenic concentration≥1 μg/g Numeric Rating Sscale≥3 at the baseline Subjects taking hormone-containing medications must be on a stable dose for 6 months prior to study start to avoid any confounding influence on sensory and pain perception Exclusion Criteria: Use of oral anti-inflammatory medications for 2 weeks prior to the study start. Use of oral anti-histamines for 2 weeks prior to the study start. Use of topical or oral anti-pruritic agents for 2 weeks prior to the study start. Use of oral neuromodulatory agents for 2 months prior to study start. Current use of chronic pain medications (including opioids, antidepressants and anti-epileptic drugs). Use of nicotine-containing products for the past 6 months prior to study start. History of basic itchy dermatological diseases before such as eczema wich may influence the judgement of drug efficacy. Unstable thyroid function within the past 6 months prior to study start to exclude thyroid-related neuropathy. Known history of central or peripheral nervous system dysfunction. History of acute hepatitis, chronic liver disease or end stage liver disease. History of human immunodeficiency virus (HIV) or acquired immune deficiency syndrome. History of neuropathy associated with chronic obstructive pulmonary disease, diabetes mellitus, documented exposure to organophosphates or heavy metals or polychlorinated biphenyls. Known nutritional deficiency (vitamin B12, vitamin D, iron or zinc) within 3 months prior to the study start. Use of illicit drugs within the past 6 months prior to study start. Lyme disease, porphyria, rheumatoid arthritis, Hansen's disease (leprosy) or use of antineoplastic chemotherapeutic agents. Patients considered by researchers that are not suitable to the study.

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
Interventional Model Description: Participants will be randomly assigned to two arms using a computer-generalized sequence of random numbers.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Naloxone<br>Naloxone at an sublingual dose of 40 mg daily will be given to each subject. | Drug: Naloxone<br>* Naloxone at an sublingual dose of 40 mg daily for one week will be given to each subject. Subjects will self-administer the drug at supervision in the primary care center.<br>|
| Placebo Comparator: Placebo<br>Sublingual placebo will be given to each subject. | Drug: Placebo<br>* Placebo will be given to each subject for one week. Subjects will self-administer the drug at supervision in the primary care center.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction in symptom of itch | Participants will be asked to report the severity of itch using a numeric rating scale (NRS) at the baseline and week 1 of the trial | 1 week | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sleeping quality | Measured by the Pittsburgh Sleep Quality Index at baseline and week 1 of the trial | 1 week | 
| Serological indicator | Level of serum beta-endorphin will be tested at baseline and week 1 of the trial | 1 week | 
| Health-related quality of life | Dermatology Life Quality Index (DLQI) at baseline and week 1 of the trial | 1 week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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arsenic exposure, naloxone, placebo, single-blind randomized trial