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NCT Number: NCT07361796

The Analgesic Efficacy and Safety of Venlafaxine for Prevention of Postherpetic Neuralgia in Patients With Acute Herpes Zoster

Postherpetic neuralgia (PHN) is the most common complication of herpes zoster (HZ) and represents a major clinical challenge due to its chronicity and impact on quality of life. Current treatments for acute HZ pain have limited efficacy in preventing PHN, highlighting the need for effective preventive strategies targeting early pathophysiological mechanisms. Venlafaxine as a plausible and clinically relevant candidate for early intervention to prevent the transition from acute HZ pain to PHN.

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Key information

Conditions

Herpes Zoster DNA Virus Infections Herpesviridae Infections Infections Nervous System Diseases Neuralgia Neuralgia, Postherpetic Neurologic Manifestations Neuromuscular Diseases Pain Pathological Conditions, Signs and Symptoms Peripheral Nervous System Diseases Postherpetic Neuralgia Signs and Symptoms Varicella Zoster Virus Infection Virus Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Beijing Tiantan Hospital, Beijing, Beijing 100070

Beijing, China

Location status: Recruiting

Location contact

Fang Luo

CONTACT

[email protected]

13611326978

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 1. Ages more than 18 years;
  • 2. Patients with onset of HZ rash less than 30 days;
  • 3. Experiencing moderate to severe HZ pain with an average pain score of at least 4 on a Numeric Rating Scale (NRS, 0 = no pain, 10 = worst possible pain);
  • 4. Aspartate aminotransferase and alanine aminotransferase levels less than twice the upper limit of normal;
  • 5. Estimated glomerular filtration rate of 30 mL/min per 1.73 m2 or higher;
  • 6. Willing to sign the informed consent form and possessing sufficient cognitive and language abilities to comply with all the study requirements.

Exclusion criteria

  • 1. HZ with head, neck, ocular, mucous membrane, cranial nerve, or central nervous system involvement or generalized HZ;
  • 2.Known hypersensitivity to venlafaxine;
  • 3.History of major depressive disorder requiring antidepressant therapy;
  • 4.History of systemic immune diseases, organ transplantation, or cancers;
  • 5.Pregnancy or lactation;
  • 6.Presence of acute or chronic pain disorders other than HZ.

Treatment and study plan

Venlafaxine combined conventional therapy

Drug

Venlafaxine will be initiated at 75 mg once daily and titrated based on pain response and tolerability before 90 days after rash onset. All participants will receive standardized analgesic management following the World Health Organization pain ladder. In addition, the group will contain conventional treatment for HZ, including NSAIDs, opioids, antiviral drugs and so on. After 90 days from rash onset, treatment will be standardized across both groups. Participants who develop persistent pain consistent with PHN will receive guideline-based management, including gabapentinoids, tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, and topical agents such as lidocaine or capsaicin, as clinically indicated.

Conventional therapy

Drug

The control group will receive conventional therapy alone before 90 days after rash onset. After 90 days from rash onset, treatment will be standardized across both groups. Participants who develop persistent pain consistent with PHN will receive guideline-based management, including gabapentinoids, tricyclic antidepressants, serotonin-norepinephrine reuptake inhibitors, and topical agents such as lidocaine or capsaicin, as clinically indicated.

Primary outcomes

  1. Incidence of PHN

    Time frame: at 90 days after rash onset

    PHN will be defined as persistent pain in the affected dermatome at 90 days after rash onset that is clinically meaningful, operationalized as an average pain score ≥ 3 on the NRS.

Secondary outcomes

  1. The average daily pain intensity

    Time frame: at weeks 1, 2, 4, 8, 12, 24, and 52

    The numeric rating scale (NRS) score is a way to quantify the degree of subjective feelings such as pain using numbers. Generally, 0 represents no pain, and 10 represents the most severe pain. A higher score indicates more severe pain.

  2. The worst numeric rating scale score

    Time frame: at weeks 1, 2, 4, 8, 12, 24, and 52

    The numeric rating scale (NRS) score is a way to quantify the degree of subjective feelings such as pain using numbers. Generally, 0 represents no pain, and 10 represents the most severe pain. A higher score indicates more severe pain.

  3. Proportion of Patients Achieving Pain Reduction

    Time frame: at weeks 1, 2, 4, 8, 12, 24, and 52

    The proportion of patients achieving a ≥ 50% and ≥ 30% reduction in mean baseline pain intensity

  4. Average weekly consumption of each analgesic class

    Time frame: at weeks 4, 8, 12, 24, and 52

  5. Herpes Zoster Severity of Illness Index

    Time frame: at weeks 1, 2, 4, 8 and 12

    The HZSOI is a severity-by-duration measure of overall pain burden associated with HZ and is typically calculated as the area under the curve of the worst pain scores over a defined period after rash onset.

  6. The 12-item Short-Form Health Survey (SF-12) score

    Time frame: at weeks 4, 8, 12, 24, and 52

    The SF-12 score assesses the health-related quality of life, capturing preferences across various health states. It assesses 8 dimensions: physical functioning, physical role limitations due to physical health, bodily pain, general health, vitality, social functioning, emotional role limitations due to emotional problems, and mental health. Scores range from 0 to 100 for each dimension, with higher scores indicating better health status.

  7. The Medical Outcomes Study Sleep Scale (MOS)

    Time frame: at weeks 4, 8, 12, 24, and 52

    The MOS is a questionnaire comprising 12 items that assess various aspects of sleep using a 6-point ordinal scale (1 indicating permanence and 6 indicating absence).

  8. Neuropathic Pain Scale

    Time frame: at or after 90 days following rash onset

    Neuropathic pain characteristics will be assessed using the Neuropathic Pain Scale in participants with developing PHN. The Neuropathic Pain Scale consists of 10 numeric rating items, each scored from 0 to 10, with higher scores indicating greater neuropathic pain severity. The scale assesses pain intensity, unpleasantness, and 8 specific pain qualities, including sharp, hot, dull, cold, sensitive, itchy, deep, and surface pain.

  9. Adverse events

    Time frame: Through study completion, an average of 52 weeks

    The incidence and proportion of adverse events will be recorded and categorized as mild, moderate, severe, or life-threatening. AEs are defined as events that arise during treatment, were absent before treatment, or worsen relative to the pretreatment state.

Study contacts

Contact information is provided by the study sponsor or research team.

Fang Luo

CONTACT

[email protected]

13611326978

Sponsors and collaborators

Lead sponsor

Beijing Tiantan Hospital

Other

Collaborators

  • Xiangya Hospital of Central South University
  • Zhongnan Hospital

Registry information

Official study title

The Analgesic Efficacy and Safety of Oral Medications (Venlafaxine) for Prevention of Postherpetic Neuralgia in Acute Herpes Zoster

Important dates

Study start
2025
Primary completion
2027
Study completion
2027
First posted
Jan 23, 2026
Registry last updated
Mar 27, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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