SEARCH · PubMed Health

Results for “Valacyclovir”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

PubMed2000

Monitoring pregnancy outcomes after prenatal drug exposure through prospective pregnancy registries: a pharmaceutical company commitment.

OBJECTIVE: Glaxo Wellcome becomes aware of prenatal exposures to its medications as early as the clinical trial phase of development. An international process for monitoring prenatal exposure to all Glaxo Wellcome medicines has been developed. For specific products there are prospective pregnancy registries. STUDY DESIGN: The registries are observational, case-registration, and follow-up studies designed to detect evidence of teratogenicity associated with specific medications. After prenatal exposure to the registry medication, pregnancies are registered prospectively, through voluntary reports by health care providers. An advisory committee of independent scientists for each registry reviews data and advises in dissemination of information. Risk of birth defects, as defined by the Centers for Disease Control and Prevention, is compared with published risks both in women in the general population and in women with the underlying condition being treated, if available. RESULTS: The following data show results from the prospective first-trimester exposures registered since establishment of each registry. The published risk of birth defects in the general population range is 3% to 5%, and the risk in women with epilepsy is 6% to 9%. The proportions of outcomes with birth defects are as follows: in the Acyclovir (antiviral medication) Pregnancy Registry (1984-1998) (19/581), 3.3% (95% confidence interval, 2.0%-5.2%); in the Lamotrigine (monotherapy and polytherapy antiepileptic medication) Pregnancy Registry (1992-September 1998) (8/123), 6.5% (95% confidence interval, 3.1%-12.8%); in the Sumatriptan (migraine medication) Pregnancy Registry (1996-October 1998) (7/183), 3.8% (95% confidence interval, 1.7%-8.0%). The Valacyclovir, Bupropion, and Naratriptan registries have insufficient data for analysis. CONCLUSION: None of the registries has provided a risk estimate exceeding that expected in the disorder treated, and no pattern of defects has been observed. Whereas information from the larger registries is reassuring regarding risk, these studies cannot rule out possible small excess risks from use of these drugs in pregnancy. Data obtained through these registries are shared with the medical community as a supplement to animal toxicology studies to assist in weighing potential risks and benefits of treatment for individual patients. The success of the registries depends on the continued willingness of the obstetrics and gynecology community to notify the registries of prenatal exposures.

Abnormalities, Drug-Induced↗

PubMedDate not supplied

Advances in the treatment of herpesvirus infection: the role of famciclovir.

Shingles (herpes zoster) is the result of reactivation of varicella-zoster virus after years of latency. The acute phase is self-limiting but is often associated with moderate-to-severe pain; postherpetic neuralgia is the most frequent and debilitating complication of shingles, occurring in 3.4 per 1000 individuals per year. In the case of genital herpes, herpes simplex virus can reactivate to cause recurrent episodes as often as several times a year, sometimes for the remainder of a person's life. Antiviral agents such as famciclovir, valacyclovir, and acyclovir can be used to shorten the course and decrease the severity of these diseases and may suppress the virus itself, thereby preventing future outbreaks of genital herpes. This article presents a brief synopsis of the etiology of herpes zoster and genital herpes and reviews 12 key studies that demonstrate the efficacy of famciclovir in the management of these two conditions.

2-Aminopurine↗

PubMed1999

New developments in the epidemiology, natural history and management of genital herpes.

The prevalence of genital herpes is increasing in several populations worldwide. Factors that may be contributing to this increase include greater numbers of sexual partners, the high frequency of asymptomatic infections, poor use of safe sexual practices, and possibly the decreased incidence of childhood oral herpes simplex virus infection. Transmission occurs via skin-to-skin or mucous membrane contact during periods of viral shedding when lesions are present but may also occur when the patient is unaware of the lesions or when lesions are not clinically apparent. This has important implications for strategies to prevent transmission of the disease. The introduction of the antiherpes agent, acyclovir, and more recently famciclovir and valacyclovir, facilitates the management of genital herpes. Treatment of first-episode genital herpes reduces the severity and duration of symptoms, time to lesion healing, and cessation of viral shedding. Episodic treatment of recurrences as they occur may be of benefit to some patients. Daily suppressive therapy significantly reduces the frequency of recurrences and asymptomatic viral shedding. Accordingly, patients who experience frequent or severe recurrences, those particularly troubled by their disease, and those who wish to reduce the frequency of asymptomatic infection generally prefer suppressive therapy. The possibility that suppressive therapy may have an impact on transmission of the disease is currently under investigation. Antiviral treatments have important implications for public health and may help reduce the psychological and psychosocial impact of genital herpes on individual patients.

Antiviral Agents↗

PubMed2000

Meeting future challenges in topical ocular drug delivery: development of an air-interfaced primary culture of rabbit conjunctival epithelial cells on a permeable support for drug transport studies.

The purpose of this study was to develop and characterize a functional air-interfaced primary culture of rabbit conjunctival epithelial cells grown on a permeable support for drug transport studies. Conjunctival epithelial cells from the pigmented rabbit were isolated, seeded at 1.2 x 10(6) cells cm(-2) on permeable Transwell filters, and cultured at the air interface using a modified PC-1 medium. Conjunctival epithelial cell layers showed a transepithelial resistance of 1.1+/-0.1 kOmega cm(2), a potential difference of 17.0+/-0.5 mV, and an equivalent short-circuit current (I(eq)) of 16.1+/-0.4 microA cm(-2). The I(eq) was reduced by 35% using 0.01 mM bumetanide, 66% using 0.1 mM ouabain, 46% using 2 mM barium chloride (all three in the basolateral fluid), and 63% using 0.3 mM NPAA in the apical fluid, consistent with active Cl(-)-secretion across the conjunctival epithelial barrier. Amiloride-sensitive Na(+) channels were absent. The permeability of the cell layers to polar solutes decreased with increased solute size, and the calculated equivalent pore size was about 8.0 nm. The Papp of beta-blockers varied with lipophilicity in a sigmoidal fashion. Uridine transport showed temperature sensitivity and directionality, favoring transport in the apical-to-basolateral direction. Apical L-carnosine uptake was reduced by 46% in the absence of an inwardly directed proton gradient, and lowering the temperature to 4 degrees C abolished direction-dependent L-carnosine uptake. Furthermore, uptake was inhibited by 73% using apical 10 mM glycyl sarcosine (a dipeptide transporter substrate) and by 60% using 1 mM L-valacyclovir (a dipeptide prodrug). In conclusion, a functional air-interfaced primary culture of rabbit conjunctival epithelial cell layers was established. This air-interfaced primary culture model may be useful for studying passive and active transport processes for ion and solute translocation in the mammalian conjunctival epithelial barrier in a defined experimental setting.

Adrenergic beta-Antagonists↗

PubMed1999

Acute varicella zoster with postherpetic hyperhidrosis as the initial presentation of HIV infection.

A 31-year-old man presented with acute pain in his left arm and hemorrhagic vesicles that followed his left 8th cervical nerve. A diagnosis of herpes zoster was made, and the patient was treated with valacyclovir. He refused testing for antibodies to HIV because he denied being at risk. Two months later he returned with postherpetic neuralgia and postherpetic hyperhidrosis in the distribution of the vesicles, which had since resolved. Serology for HIV at this visit was positive, and the patient admitted to having sexual relations with prostitutes. Six months later the patient was being treated with triple antiretroviral therapy, and all signs and symptoms of postherpetic zoster had resolved. This case report documents the need for HIV testing in patients with unusual presentations of herpes zoster even if they initially deny being at risk.

AIDS-Related Opportunistic Infections↗

PubMed1998

Monitoring pregnancy outcomes following prenatal drug exposure through prospective pregnancy registries and passive surveillance: a pharmaceutical company commitment.

Objectives: Glaxo Wellcome (G.W.) becomes aware of prenatal exposures to its medications from as early as the clinical trial phase of development. An international process for monitoring prenatal exposure to all G.W. medicines has been developed utilizing a passive surveillance system and, for specific products, pregnancy registries. Additionally, G.W. jointly sponsors the multi-company Antiretroviral and North American Antiepileptic Drug (AED) Pregnancy Registries.Study Design: The registries are observational, case-registration and follow-up studies designed to detect evidence of teratogenicity associated with specific medications. Pregnancies are registered prospectively following prenatal exposure to the registry medication. An advisory committee for each registry reviews data and assists in dissemination of information. Committee members include independent scientists with expertise in fields such as obstetrics, teratology, epidemiology, pediatrics, and the relevant therapeutic areas.Results: The following data are from the prospective first-trimester exposures in each registry. Through December 1996, the proportion of outcomes in the Acyclovir Pregnancy Registry with birth defects (n = 17/505) is 3.4% (95% CI 2.0%, 5.4%). Through March 1997, the proportion of outcomes in the Lamotrigine Pregnancy Registry with birth defects (n = 4/76) is 5.3% (95% CI 1.7%, 13.6%). Through April 1997, the proportion of outcomes in the Sumatriptan Pregnancy Registry with birth defects (n = 5/148) is 3.4% (95% CI 1.3%, 8.1%). The newer Valacyclovir and Bupropion Pregnancy Registries have insufficient data for analysis. None of the registries have provided a risk estimate exceeding that expected in the general population, and no pattern of defects has been observed.Conclusions: The outcomes accumulated to date represent a sample of insufficient size for reaching conclusions regarding the possible teratogenic risk of using these drugs in pregnancy. Data obtained through these registries are shared with the medical community as a supplement to animal toxicology studies and to assist in weighing potential risks and benefits of treatment for individual patients. The success of the registries depends on the continued willingness of the OB/GYN community to notify the registries of prenatal exposures.

Journal Article↗

PubMed2000

Recent advances in the therapy and prevention of CMV infections.

The introduction of highly active antiretroviral therapy (HAART) for HIV has had a major impact on the treatment of CMV disease in HIV-infected individuals. There is mounting evidence that in patients with CMV retinitis who have a sustained response to HAART, CMV maintenance treatment can be discontinued without relapse of retinitis. In HAART-naïve individuals with newly diagnosed CMV retinitis, the optimal timing for the initiation of HAART relative to the start of anti-CMV treatment is currently unknown. New local therapies for CMV retinitis (e.g. ganciclovir implant, the new antisense compound fomivirsen) provide treatment options in situations where high local drug delivery is warranted. A treatment algorithm for CMV disease in the HAART era is proposed. In the transplant setting, ganciclovir and foscarnet remain the major compounds used for treatment of CMV disease. In marrow and stem cell transplant recipients, CMV pneumonia still carries a high mortality. Ganciclovir in combination with CMV-specific immunoglobulin or regular intravenous IG remains the treatment of choice for CMV pneumonia; extended antiviral maintenance for several months is recommended in patients with continued immunosuppression. Preemptive treatment based on virologic markers (e.g. pp65 antigenemia, CMV DNA) has been very successful in reducing the incidence of early CMV disease in the transplant setting. The duration of preemptive treatment should be guided by the underlying immunosuppression and virologic markers. Late CMV disease is a challenge in marrow and stem cell transplant recipients, and occurs increasingly in highly immunosuppressed solid organ transplant recipients as well. Recent advances in prophylaxis strategies include oral ganciclovir for liver transplant recipients and valacyclovir for kidney transplant recipients.

AIDS-Related Opportunistic Infections↗

PubMed1998

5'-Amino acid esters of antiviral nucleosides, acyclovir, and AZT are absorbed by the intestinal PEPT1 peptide transporter.

PURPOSE: General use of nucleoside analogues in the treatment of viral infections and cancer is often limited by poor oral absorption. Valacyclovir, a water soluble amino acid ester prodrug of acyclovir has been reported to increase the oral bioavailability of acyclovir but its absorption mechanism is unknown. This study characterized the intestinal absorption mechanism of 5' -amino acid ester prodrugs of the antiviral drugs and examined the potential of amino acid esters as an effective strategy for improving oral drug absorption. METHODS: Acyclovir (ACV) and Zidovudine (AZT) were selected as the different sugar-modified nucleoside antiviral agents and synthesized to L-valyl esters of ACV and AZT (L-Val-ACV and L-Val-AZT), D-valyl ester of ACV (D-Val-ACV) and glycly ester of ACV (Gly-ACV). The intestinal absorption mechanism of these 5' -amino acid ester prodrugs was characterized in three different experimental systems; in situ rat perfusion model, CHO/hPEPT1 cells and Caco-2 cells. RESULTS: Testing 5' -amino acid ester prodrugs of acyclovir and AZT, we found that the prodrugs increased the intestinal permeability of the parent nucleoside analogue 3- to 10-fold. The dose- dependent permeation enhancement was selective for L-amino acid esters. Competitive inhibition studies in rats and in CHO cells transfected with the human peptide transporter, hPEPT1, demonstrated that membrane transport of the prodrugs was mediated predominantly by the PEPT1 H+/dipeptide cotransporter even though these prodrugs did not possess a peptide bond. Finally, transport studies in Caco-2 cells confirmed that the 5' - amino acid ester prodrugs enhanced the transcellular transport of the parent drug. CONCLUSIONS: This study demonstrates that L-amino acid-nucleoside chimeras can serve as prodrugs to enhance intestinal absorption via the PEPT1 transporter, providing a novel strategy for improving oral therapy of nucleoside drugs.

Acyclovir↗

PubMed2000

Varicella zoster meningoencephalitis following treatment for dermatomal zoster in an alloBMT patient.

Herpes zoster infections are frequently observed after allogeneic bone marrow transplantation (alloBMT). In the majority of cases, the infection is restricted to specific dermatomes and responds to oral acyclovir, without visceral dissemination. We report the case of a 40-year-old male who developed dermatomal herpetic infection 8 months post alloBMT. The herpetic rash responded well to treatment with high-dose oral acyclovir. However, within a week of cessation of therapy, the patient re-presented with dermatomal zoster and meningoencephalitis. Although the cutaneous lesions resolved with intravenous acyclovir, clinical features of meningoencephalitis persisted, along with evidence of varicella zoster virus (VZV) DNA in cerebrospinal fluid (CSF). A satisfactory response to treatment was observed only after the addition of intravenous foscarnet to acyclovir. Based on our experience with this patient, we suggest that in a subset of alloBMT recipients, late dermatomal herpes zoster infections may respond only partially to treatment with standard oral acyclovir. The use of oral acyclovir preparations with higher bioavailability (valacyclovir) or intravenous acyclovir early on may prevent the considerable morbidity associated with disseminated zoster infection. Bone Marrow Transplantation (2000) 26, 795-796.

Acyclovir↗

PubMed2000

Antimicrobial prophylaxis in dermatology.

Few circumstances in dermatology warrant antimicrobial prophylaxis. In cutaneous surgery postoperative infections are too infrequent and insufficiently severe to justify preventive antibiotics, except rarely. Petrolatum is as effective as, and cheaper than, topical antibiotic ointment to cover surgical wounds. In patients with numerous staphylococcal skin infections, oral clindamycin 150 mg every day for 3 months safely reduces further episodes. For recurrent cellulitis, oral penicillin or erythromycin 250 mg twice daily or monthly intramuscular benzathine penicillin decreases subsequent attacks. In patients with frequent episodes of genital or labial herpes simplex an antiviral agent such as valacyclovir 500 mg to 1 g every day is effective as a suppressant.

Anti-Bacterial Agents↗

PubMed1999

New therapies and prevention strategies for genital herpes.

Genital herpes is among the most prevalent sexually transmitted diseases. Optimal management of genital herpes includes accurate diagnosis, antiviral therapy, and counseling of patients about complications and transmission of herpes simplex virus (HSV). Antiviral therapy offers significant palliation, and the option of episodic or suppressive treatment should be offered to all patients with genital herpes. Valacyclovir and famciclovir are two newer antiviral agents that are effective and safe for the treatment of genital herpes. Prevention strategies for sexual and perinatal transmission of HSV have not been well defined. Availability of type-specific serological tests for HSV antibodies may assist in identifying persons at risk for acquiring or transmitting HSV infection. Further research is needed to define strategies to prevent the spread of this epidemic infection.

AIDS-Related Opportunistic Infections↗

PubMed1998

The Albion Street Centre database, Sydney, Australia.

The Albion Street Centre was established in 1985 as an HIV testing and early management center. More than 22,000 people have been screened for HIV and other blood-borne infections at the Centre, and approximately 3,600 people with HIV/AIDS have been managed there. Approximately 1,600 patients with various stages of HIV disease are currently managed at the Centre by a staff of 60 health care professionals and about 1,000 volunteers. The Albion Street Centre's computer database began recording selected demographic, epidemiologic, clinical, and laboratory characteristics when the first patient presented in 1985. Since then, the complexity and utilization of the database has increased in parallel with improvement in the understanding of the natural history and pathogenesis of HIV infection. Over 100 peer-reviewed publications and presentations have been produced from the database and 45 clinical trials have used the database to identify potential subjects. All data are de-identified and are protected by multiple password codes. Approximately 700 variables are collected from each HIV-positive patient at the initial visit to the Centre and up to 200 variables are added at each subsequent routine clinic visit. The variables collected include the following: standard epidemiologic characteristics; transmission and behavioral parameters, clinical signs and symptoms; laboratory test results; treatments; nutritional history; body composition parameters; psychological assessment results; and management history, including neuropsychological testing. The overall number and characteristics of patients recorded in the database are reported monthly, and are used to plan services, for prevention and educational programs, and as an indicator of the effectiveness of campaigns to encourage HIV-positive people to attend clinics for early management. When these patients have been identified they are invited to participate in the study. Individual patient records are identified and accessed if they meet certain criteria for flagging. For example, patients who have lost more than 5% of their maximal weight are flagged and referred to the dietician for assessment. Further uses for the database are to identify cohorts of patients who are seroconverters and to follow their natural history-the Centre has over 250 patients for whom a documented HIV-positive test has been obtained within 12 months of a documented HIV-negative test; to investigate clinical observations that have been associated with particular drug therapy, e.g., investigation of the reported association between the use of valacyclovir and the thrombotic thrombocytopenic purpura/hemolytic uremic syndrome (TTP/HUS)-like complex showed patients with terminal-stage AIDS demonstrated this syndrome independently of their therapy and probably as a consequence of multiorgan failure; and to document the relationship between nutritional intervention and survival, for which use of the database enabled an historical cohort that matched the cases under investigation to be selected. In conclusion, the database is a dynamic and integral part of the assessment, management, and research program of the Albion Street Centre, where it is used by all professional staff.

Adolescent↗

PubMed1996

Varicella-zoster virus.

Varicella-zoster virus (VZV) is a ubiquitous human alphaherpesvirus that causes varicella (chicken pox) and herpes zoster (shingles). Varicella is a common childhood illness, characterized by fever, viremia, and scattered vesicular lesions of the skin. As is characteristic of the alphaherpesviruses, VZV establishes latency in cells of the dorsal root ganglia. Herpes zoster, caused by VZV reactivation, is a localized, painful, vesicular rash involving one or adjacent dermatomes. The incidence of herpes zoster increases with age or immunosuppression. The VZV virion consists of a nucleocapsid surrounding a core that contains the linear, double-stranded DNA genome; a protein tegument separates the capsid from the lipid envelope, which incorporates the major viral glycoproteins. VZV is found in a worldwide geographic distribution but is more prevalent in temperate climates. Primary VZV infection elicits immunoglobulin G (IgG), IgM, and IgA antibodies, which bind to many classes of viral proteins. Virus-specific cellular immunity is critical for controlling viral replication in healthy and immunocompromised patients with primary or recurrent VZV infections. Rapid laboratory confirmation of the diagnosis of varicella or herpes zoster, which can be accomplished by detecting viral proteins or DNA, is important to determine the need for antiviral therapy. Acyclovir is licensed for treatment of varicella and herpes zoster, and acyclovir, valacyclovir, and famciclovir are approved for herpes zoster. Passive antibody prophylaxis with varicella-zoster immune globulin is indicated for susceptible high-risk patients exposed to varicella. A live attenuated varicella vaccine (Oka/Merck strain) is now recommended for routine childhood immunization.

Acyclovir↗

PubMed1998

Treatment of acyclovir-resistant herpetic ulceration with topical foscarnet and antiviral sensitivity analysis.

BACKGROUND: Herpes simplex virus (HSV) can produce persistent mucocutaneous disease in patients with the acquired immunodeficiency syndrome (AIDS). In this case report, we evaluate the efficacy, safety and viral resistance after topical foscarnet in severe genital ulceration due to acyclovir-resistant HSV-2. CASE REPORT: A 45-year-old African woman was known for an HIV infection with severe immunosuppression (CD4 <100/mm3). She had received a long-term prophylaxis with acyclovir (400 mg b.i.d.) for a recurrent genital herpes. Few weeks after stopping this prophylaxis, she developed large genital ulcerations progressing despite valacyclovir treatment (1,000 mg t.i.d.). Cultures were positive for HSV-2, resistance to acyclovir was shown by the plaque reduction assay and topical foscarnet was tried. Treatment consisted of a 20-min application of topical foscarnet 2.4% twice a day. Dramatic improvement was observed with rapid antalgia, and cicatrization of the genital ulcerations was observed after 50 days. HSV could not be detected on the mucosal surface. Initially, HSV-2 was resistant to acyclovir but sensitive to foscarnet. After 1 month of topical treatment, HSV-2 became sensitive to acyclovir and was still sensitive to foscarnet. Finally, after 6 weeks of treatment, no virus could be detected by culture. CONCLUSION: Topical foscarnet (2.4%) is a convenient treatment for chronic genital herpes. Resistance to acyclovir disappears few weeks after stopping this drug and sensitivity to foscarnet persists during the 50 days of treatment.

Acyclovir↗

PubMed1999

Antiinfectives update: focus on treatment and prevention of viral and associated infections.

OBJECTIVE: To review the clinically significant antiinfectives approved by the Food and Drug Administration (FDA) since 1996, with an emphasis on agents used for treatment, prevention, or suppression of infection in immunocompromised individuals. DATA SOURCES: A MEDLINE search covering November 1994 to March 1998 was conducted to identify all antiinfectives (new medications and old medications with new indications) and the pertinent literature for review. The search was updated in August 1998 and supplemented with an FDA listing of approved drugs to enhance completeness. STUDY SELECTION: Clinically relevant studies were selected to highlight specific points about each medication. Preclinical publications were used when sufficient information was not available from clinical trials and this information was needed for clinical practice. CONCLUSIONS: Several new and promising antiretroviral agents (stavudine, lamivudine, saquinavir soft-gel capsules, nelfinavir, efavirenz) have been approved, which may allow more options to control HIV viremia. New options for treatment, prevention, and suppression of infections in immunocompromised individuals include azithromycin, cidofovir, famciclovir, valacyclovir, and itraconazole suspension. Liposomal-based amphotericin products may be associated with less toxicity than conventional amphotericin B; however, superior efficacy has not been proven.

AIDS-Related Opportunistic Infections↗

PubMed1999

Recent advances in varicella-zoster virus infection.

Varicella-zoster virus has developed a complex strategy that allows it to remain latent in the body and avoid destruction by the immune system. Although varicella and zoster have been recognized since antiquity, several new clinical syndromes--including chronic chickenpox with persistent verrucous lesions and disseminated varicella without skin lesions--have been noted in patients with AIDS. Acyclovir has been the mainstay for treating severe varicella-zoster virus infections; however, newer antiviral agents, including valacyclovir and famciclovir, have expanded therapeutic options for treating adults with herpes zoster. The recently licensed live attenuated vaccine for varicella-zoster virus is effective in preventing chickenpox, and the vaccine's ability to stimulate immunity in seropositive adults suggests a promising strategy with which to modify the course of herpes zoster.

Adult↗

PubMed2000

[Clinical manifestations of the subfamily alpha-herpesvirinae in childhood].

Herpes simplex virus(HSV) and varicella-zoster virus(VZV) belonging to the subfamily of alpha-herpesvirinae have the capacity to establish latent infection in neural tissues and to reactivate from these sites. HSV infection is characterized by a vesicular eruption, fever, and other constitutional symptoms but frequently inapparent both in primary and recurrent infections. However, the infection produces a wide spectrum of illness ranging from the trivial fever blisters to the most severe fatal sporadic encephalitis and neonatal infection. In contrast, VZV develops varicella, a common contagious disease of childhood during primary infection and zoster by reactivation of latent virus acquired during varicella. In normal children, the systemic symptoms of both diseases are mild, whereas serious complications are often observed in children with deficiencies in cell-mediated immunity. Acyclovir has been the drug of choice for treatment of severe infection with HSV and VZV for approximately 2 decades. Now, two new agents, valacyclovir and famciclovir will supplant acyclovir for certain indications.

Alphaherpesvirinae↗

PubMed2000

Management of herpes zoster (shingles) and postherpetic neuralgia.

Herpes zoster (commonly referred to as "shingles") and postherpetic neuralgia result from reactivation of the varicella-zoster virus acquired during the primary varicella infection, or chickenpox. Whereas varicella is generally a disease of childhood, herpes zoster and post-herpetic neuralgia become more common with increasing age. Factors that decrease immune function, such as human immunodeficiency virus infection, chemotherapy, malignancies and chronic corticosteroid use, may also increase the risk of developing herpes zoster. Reactivation of latent varicella-zoster virus from dorsal root ganglia is responsible for the classic dermatomal rash and pain that occur with herpes zoster. Burning pain typically precedes the rash by several days and can persist for several months after the rash resolves. With postherpetic neuralgia, a complication of herpes zoster, pain may persist well after resolution of the rash and can be highly debilitating. Herpes zoster is usually treated with orally administered acyclovir. Other antiviral medications include famciclovir and valacyclovir. The antiviral medications are most effective when started within 72 hours after the onset of the rash. The addition of an orally administered corticosteroid can provide modest benefits in reducing the pain of herpes zoster and the incidence of postherpetic neuralgia. Ocular involvement in herpes zoster can lead to rare but serious complications and generally merits referral to an ophthalmologist. Patients with postherpetic neuralgia may require narcotics for adequate pain control. Tricyclic antidepressants or anticonvulsants, often given in low dosages, may help to control neuropathic pain. Capsaicin, lidocaine patches and nerve blocks can also be used in selected patients.

Acyclovir↗