Duloxetine for PHN

Study Overview
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Brief Summary
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In this study, the investigators aim to investigate the preventive efficacy of prophylactic oral duloxetine during acute herpes zoster on postherpetic neuralgia and its safety.

Detailed Description
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Postherpetic neuralgia is a common complication of herpes zoster. Several interventions have been investigated for the treatment of postherpetic neuralgia, however, there is a lack of preventive intervention on postherpetic neuralgia. A recent retrospective study revealed that the administration of gabapentin during the acute herpes zoster period significantly decreased the incidence of postherpetic neuralgia. In the present study, the investigators aim to conduct a prospective, randomized, open-label, endpoint blinded study to investigate the preventive efficacy of prophylactic use of duloxetine on postherpetic neuralgia.

Official Title
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Prophylactic Duloxetine Administration During Acute Herpes Zoster Prevents Postherpetic Neuralgia

Conditions
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Postherpetic Neuralgia

Intervention / Treatment
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* Drug: Duloxetine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ages more than 50 years; diagnosed with uncomplicated acute herpes zoster; presents with vesicles within 72 hours; has an average pain score of at least 40/100 mm on a visual analog scale (VAS, 0 = no pain, 100 = worst possible pain, at opposite ends of a 100-mm line). Exclusion Criteria: refuses to participate or to provide written informed consent; Zung Self-Rating Depression Scale raw score of more than 50 points; herpes zoster that involves with head, neck, ocular, mucous membrane, cranial nerve, or central nervous system; has hemorrhagic or necrotizing lesions, satellite lesions, abnormal vesicles or acute retinal necrosis; has been on immunosuppressive therapy or mono- or multi-pharmacotherapy that involves any tricyclic antidepressant, valacyclovir, duloxetine or cytotoxic medications before acute HZ onset; has been diagnosed with hepatic, renal or immune dysfunction; during pregnancy or breastfeeding at the time; hypersensitivity to the study drugs; has contraindications to valacyclovir or duloxetine; HZ vaccinated.

Ages Eligible for Study
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Minimum Age: 50 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Duloxetine<br>Apart from the standard treatment, participants in the Duloxetine Arm will be administered with oral duloxetine (up to 60 mg per day) in the acute herpes zoster period. | Drug: Duloxetine<br>* Oral Duloxetine (up to 60 mg per day) will be given, titrated, tapered in accordance with the pain intensity during the acute herpes zoster period.<br>|
| No Intervention: Control<br>Participants will be given the standard treatment during the acute herpes zoster period. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Preventive efficacy of Postherpetic neuralgia | The proportion of participants in the Interventional Arm who gain a 0 score in a 100 mm visual analgue scale (0 mm = no pain, 100 mm = the most imaginable pain) | 12 weeks after the reactivation of acute herpes zoster | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Averaged weekly VAS score | Averaged weekly VAS score of each participant | up to 12 weeks | 
| Averaged weekly analgesic consumption | Averaged weekly consumption per analgesic of each participant | up to 12 weeks | 
| Patients' overall quality of life | 12-item Short-Form Health Survey (SF-12) | At the end of Weeks 4, 8, and 12 | 
| Sleep quality | Pittsburgh Sleep Quality Index (PSQI) self-rated questionnaire | At the end of Weeks 4, 8, and 12 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Postherpetic Neuralgia, Duloxetine