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.
Highlights
Postherpetic neuralgia (PHN) is a chronic neuropathic pain that results from alterations of the peripheral nervous system in areas affected by the herpes zoster virus
Gabapentin is an anticonvulsant type of analgesic that could prevent the onset of PHN by its antihypersensitivity action in dorsal horn neurons
Herpes zoster (HZ), often called shingles, is a common disease characterized by a painful, unilateral vesicular eruption that is caused by reactivation of a dormant varicella zoster virus within the dorsal root or cranial nerve ganglia
Summary
Postherpetic 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 most frequent complication following an acute episode of HZ infection is postherpetic neuralgia (PHN), a chronic and debilitating neuropathic pain syndrome that is refractory to most therapeutic strategies. The authors of a recent systematic review reported that the incidence of HZ infection was between 3 and 12 cases per 1000 patient-years for individuals older than 50 years of age, and that the overall risk of PHN ranges from 5% to more than 30% [2]. When PHN is defined as pain lasting for 3 months, the incidence is 18% in individuals older than 50 years of age and 33% in individuals older than 80 years of age [3]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
