Efficacy of gabapentin for prevention of postherpetic neuralgia: study protocol for a randomized controlled clinical trial

Abstract

BackgroundPostherpetic neuralgia (PHN) is a chronic neuropathic pain that results from alterations of the peripheral nervous system in areas affected by the herpes zoster virus. The symptoms include pain, paresthesia, dysesthesia, hyperalgesia, and allodynia. Despite the availability of pharmacological treatments to control these symptoms, no treatments are available to control the underlying pathophysiology responsible for this disabling condition.Methods/designPatients with herpes zoster who are at least 50 years old and have a pain score of 4 or higher on a visual analogue scale (VAS) will be recruited. The aim is to recruit 134 patients from the practices of general physicians. Participants will be randomized to receive gabapentin to a maximum of 1800 mg/day for 5 weeks or placebo. Both arms will receive 1000-mg caplets of valacyclovir three times daily for 7 days (initiated within 72 h of the onset of symptoms) and analgesics as needed. The primary outcome measure is the percentage of patients with a VAS pain score of 0 at 12 weeks from rash onset. The secondary outcomes measures are changes in quality of life (measured by the SF-12 questionnaire), sleep disturbance (measured by the Medical Outcomes Study Sleep Scale), and percentage of patients with neuropathic pain (measured by the Douleur Neuropathique in 4 Questions).DiscussionGabapentin is an anticonvulsant type of analgesic that could prevent the onset of PHN by its antihypersensitivity action in dorsal horn neurons.Trial registrationISRCTN Registry identifier: ISRCTN79871784. Registered on 2 May 2013.Electronic supplementary materialThe online version of this article (doi:10.1186/s13063-016-1729-y) contains supplementary material, which is available to authorized users.

Herpes Zoster in the Older Adult

“…2, 3, 5, 26–28 It is considered the most debilitating sequelae of HZ since it impairs the affected individual’s quality of life across all 4 health domains: physical, psychological, functional and social. 27 …”

“…6 There is currently a randomized placebo controlled trial to evaluate the effectiveness of gabapentin in the prevention of PHN. 27 …”

Role for the Ventral Posterior Medial/Posterior Lateral Thalamus and Anterior Cingulate Cortex in Affective/Motivation Pain Induced by Varicella Zoster Virus

“…Treatment of VZV infected animals with antivirals, opioids or NSAIDS is not highly effective, mirroring results in humans with pain after VZV infection (Rowbotham and Fields, 1996 ; Dalziel et al, 2004 ; Garry et al, 2005 ; Hasnie et al, 2007 ). Both sodium channel blockers and gabapentin can effectively treat VZV-induced pain in animals and humans (Garry et al, 2005 ; Hasnie et al, 2007 ; Rullán et al, 2017 ; Stinson et al, 2017 ). Thus, the rat model reflects aspects of the human disease and would provide information as to the mechanism by which VZV induces pain.…”

Ju Re Ba Du therapy for Postherpetic neuralgia

“…[ 16 , 17 ] Postherpetic neuralgia (PHN) is the most serious complications in HZ, is characterized by severe pain, its incidence of 5% to 30%, when patients older than 85 years old was 50%, and the higher incidence of pain and sustainable for several months to several years, the serious influence the patient's quality of life, brings the serious economic burden to society, caused a public health problem. [ 18 , 19 ]…”