valacyclovir and Neuralgia

Topics: 2-Aminopurine; Acyclovir; Amines; Antidepressive Agents, Tricyclic; Antiviral Agents; Arabinofuranosyluracil; Cyclohexanecarboxylic Acids; Famciclovir; Gabapentin; gamma-Aminobutyric Acid; Herpes Zoster; Humans; Neuralgia; Valacyclovir; Valine

Herpes zoster has been known since ancient times. It is a ubiquitous disease, occurring sporadically without any seasonal preference and is caused by the varicella-zoster virus. It may be defined as an endogenous relapse of the primary infection varicella. Herpes zoster is characterised by typical efflorescences in the innervation region of a cranial or spinal nerve and starts and ends with pain of varying intensity. Currently, several antiviral drugs are approved and many studies have shown that antiviral therapy, started early in the course of disease, can significantly reduce the risk and the duration of postherpetic neuralgia in elderly patients. The effects of all antivirals discussed in this article, given either orally or intravenously, are comparable with regards to the resolution of virus replication, prevention of dissemination of skin lesions and reduction of acute herpes zoster pain. Valaciclovir (valacyclovir), famciclovir and brivudine (brivudin) are comparably effective in the reduction of the incidence and/or prevention of zoster-associated pain and postherpetic neuralgia. Brivudine 125mg once daily is as effective as famciclovir 250mg three times daily in reducing the prevalence and the duration of zoster-associated pain and postherpetic neuralgia, especially if therapy is combined with a structured-pain therapy. The intensity of the therapy for pain should depend on the intensity of the pain that it is treating. Famciclovir and brivudine offer an advantage over other antivirals because they are administered less frequently; this is particularly relevant for elderly patients who may already be taking a number of medications for other diseases. Therefore, antiviral therapy in combination with adequate pain management should be given to all elderly patients as soon as herpes zoster is diagnosed.

Topics: 2-Aminopurine; Acyclovir; Age Factors; Aged; Analgesics; Antiviral Agents; Bromodeoxyuridine; Drug Therapy, Combination; Famciclovir; Herpes Zoster; Humans; Neuralgia; Pain Measurement; Valacyclovir; Valine

With the US population aging steadily, herpes zoster represents a growing contributor to diminished quality of life. Dermatologic manifestations appear as immunity declines with age but rarely pose a significant threat, except in instances when ocular structures are involved. Pain is of more concern, because it usually accompanies and may even precede and persist after acute eruptions. In most young patients, pain is transient and bearable. Unfortunately, in the elderly--who are at highest risk for herpes zoster--pain is often more prolonged and more intense. In spite of a wide spectrum of interventions, palliative efforts remain rather ineffectual. At present, intervening as early as possible, ideally within 48 to 72 hours of disease onset, offers the greatest chance of minimizing neurologic sequelae. Inoculation with varicella vaccine in patients between ages 55 and 65 may prove to boost cell-mediated immunity sufficiently so that recrudescence of the varicella virus can be relegated to the annals of history.

Topics: 2-Aminopurine; Acute Disease; Acyclovir; Aged; Antiviral Agents; Chronic Disease; Famciclovir; Herpes Zoster; Humans; Neuralgia; Risk Factors; Valacyclovir; Valine

Topics: 2-Aminopurine; Acyclovir; Aged; Antiviral Agents; Double-Blind Method; Famciclovir; Gastrointestinal Diseases; Headache; Herpes Zoster; Humans; Middle Aged; Nausea; Neuralgia; Pain; Prospective Studies; Time Factors; Treatment Outcome; Valacyclovir; Valine

Acyclovir treatment of acute herpes zoster speeds rash healing and decreases pain and ocular complications. The limited oral bioavailability of acyclovir necessitates frequent dosing. Valaciclovir, the l-valyl ester of acyclovir, is rapidly and almost completely converted to acyclovir in vivo and gives three- to fivefold increases in acyclovir bioavailability. In a randomized, double-blind, multicenter study, the safety and efficacy of oral valaciclovir given at a dosage of 1,000 mg three times daily for 7 or 14 days and oral acyclovir given at a dosage of 800 mg five times daily for 7 days were compared in immunocompetent adults aged > or = 50 years with herpes zoster. Patients were evaluated for 6 months. The intent-to-treat analysis (1,141 patients) showed that valaciclovir for 7 or 14 days significantly accelerated the resolution of herpes zoster-associated pain (P = 0.001 and P = 0.03, respectively) compared with acyclovir; median pain durations were 38 and 44 days, respectively, versus 51 days for acyclovir. Treatment with valaciclovir also significantly reduced the duration of postherpetic neuralgia and decreased the proportion of patients with pain persisting for 6 months (19.3 versus 25.7%). However, there were no differences between treatments in pain intensity or quality-of-life measures. Cutaneous manifestations resolved at similar rates in all groups. Adverse events were similar in nature and prevalence among groups, and no clinically important changes occurred in hematology or clinical chemistry parameters. Thus, in the management of immunocompetent patients > or = 50 years of age with localized herpes zoster, valaciclovir given at 1,000 mg three times daily for 7 days accelerates the resolution of pain and offers simpler dosing, while it maintains the favorable safety profile of acyclovir.

Topics: Acyclovir; Administration, Oral; Aged; Aged, 80 and over; Analgesics; Antiviral Agents; Double-Blind Method; Drug Administration Schedule; Female; Herpes Zoster; Herpes Zoster Ophthalmicus; Humans; Immunocompetence; Male; Middle Aged; Neuralgia; Pain; Quality of Life; Valacyclovir; Valine

Topics: Acyclovir; Adult; Antiviral Agents; DNA, Viral; Female; Herpes Zoster; Herpesvirus 3, Human; Humans; Lower Extremity; Neuralgia; Pregnancy; Pregnancy Complications, Infectious; Treatment Outcome; Valacyclovir; Valine

Fifty-four patients with herpes zoster were treated with valacyclovir. On treatment days 1, 8, and 15, pain was scored and saliva examined for varicella-zoster virus (VZV) DNA. VZV DNA was found in every patient the day treatment was started and later disappeared in 82%. There was a positive correlation between the presence of VZV DNA and pain and between VZV DNA copy number and pain (P <.0005). VZV DNA was present in 1 patient before rash and in 4 after pain resolved and was not present in any of 6 subjects with chronic pain or in 14 healthy subjects. Analysis of human saliva has potential usefulness in the diagnosis of neurological disease produced by VZV without rash.

Topics: Acyclovir; Adult; Aged; Aged, 80 and over; Antiviral Agents; Biomarkers; Case-Control Studies; Cohort Studies; DNA, Viral; Female; Herpesvirus 3, Human; Humans; Male; Middle Aged; Neuralgia; Saliva; Valacyclovir; Valine; Zoster Sine Herpete

Postherpetic neuralgia (PHN) is a serious complication of herpes zoster that has a predilection for older individuals. PHN is often associated with significant morbidity, and it can cause insomnia, fatigue, depression and interference with daily activities in affected individuals. Treatment for PHN is initiated with antivirals during the acute herpes zoster outbreak. Acyclovir (Zoviraxr, GlaxoSmithKline), valacyclovir (Valtrex, GlaxoSmithKline) or famciclovir (Famvir, Novartis) can be used to treat herpes zoster, and all three have been shown to reduce the duration of the herpetic rash and zoster-associated pain. These antivirals are most effective when used within the first 72 hours of the onset of the rash. Side-effects of these antivirals are low and include nausea, vomiting, abdominal pain and headache. Other treatment options for PHN include topical analgesics, opioid analgesics, tricyclic antidepressants and gabapentin. Because of the complexity of PHN, most patients require a combination of treatment modalities for adequate pain relief.

Topics: 2-Aminopurine; Acyclovir; Age Factors; Aged; Amines; Analgesics; Analgesics, Opioid; Antidepressive Agents, Tricyclic; Antiviral Agents; Cyclohexanecarboxylic Acids; Drug Therapy, Combination; Famciclovir; Gabapentin; gamma-Aminobutyric Acid; Herpes Zoster; Humans; Middle Aged; Neuralgia; Prodrugs; Risk Factors; Time Factors; Valacyclovir; Valine

The investigation was aimed to determine prognostic factors related to postherpetic neuralgia (PHN), and treatment options for preventing PHN. The data showed 34 (17.0%) out of 188 patients with herpes zoster had severe pain after 4 weeks, and 22 (11.7%) after 8 weeks, compared with 109 (58.0%) at presentation. The age (>/=50 yr), surface area involved (>/=9%), and duration of severe pain (>/=4 weeks) might be the main factors that lead to PHN. On the other hand, gender, dermatomal distribution, accompanied systemic conditions, and interval between initial pain and initiation of treatment might not be implicated in PHN. The subjects were orally received antiviral (valacyclovir), tricyclic antidepressant (amitriptyline), and analgesic (ibuprofen) as the standard treatment in the group 1. In addition to the standard medication, lidocaine solution was sub- and/or perilesionally injected in the group 2, while lidocaine plus prilocaine cream was topically applied to the skin lesions in the group 3. The rates of PHN in the 3 treatment groups were not significantly different, suggesting adjuvant anesthetics may not be helpful to reduce the severity of pain.

Topics: Acyclovir; Adolescent; Adult; Aged; Amitriptyline; Anti-Inflammatory Agents, Non-Steroidal; Antidepressive Agents, Tricyclic; Antiviral Agents; Child; Drug Therapy, Combination; Female; Herpes Zoster; Humans; Ibuprofen; Male; Middle Aged; Neuralgia; Prognosis; Time Factors; Valacyclovir; Valine

Famciclovir and valaciclovir were approved for use in the treatment of herpes zoster despite controversy over antiviral therapy in zoster due to high costs and uncertain benefits. To explore these issues, a Markov decision model was developed, and the incremental cost effectiveness of antiviral treatment for herpes zoster was estimated using these agents compared with no antiviral therapy. A third-party payer perspective was taken. Sensitivity analyses were performed, modeling differences in antiviral efficacy, postherpetic neuralgia (PHN) risk, and other illness parameters. Treatment of severely symptomatic acute zoster was found reasonable from a cost-effectiveness standpoint in base-case and worst-case scenarios. Treatment of mildly symptomatic acute zoster was more expensive but would likely be considered cost effective in scenarios where PHN risk was higher, PHN duration longer, or antiviral shortening of PHN greater. Further research comparing antiviral efficacy in herpes zoster is needed.

Topics: 2-Aminopurine; Acute Disease; Acyclovir; Aged; Aged, 80 and over; Antiviral Agents; Computer Simulation; Cost-Benefit Analysis; Famciclovir; Herpes Zoster; Humans; Markov Chains; Middle Aged; Models, Economic; Neuralgia; Risk Factors; Valacyclovir; Valine

Topics: 2-Aminopurine; Acyclovir; Antiviral Agents; Clinical Trials as Topic; Famciclovir; Herpes Zoster; Humans; Neuralgia; Valacyclovir; Valine