FV-100 versus valacyclovir for the prevention of post-herpetic neuralgia and the treatment of acute herpes zoster-associated pain: A randomized-controlled trial

Efficacy and safety of intravenous fosphenytoin for patients with acute herpes zoster-associated pain: A placebo-controlled randomized trial

Acute zoster-associated pain develops in most patients with herpes zoster. Nonopioid analgesics are usually used to treat acute zoster-associated pain but are frequently ineffective. We administered intravenous fosphenytoin, the prodrug of phenytoin, to patients with acute zoster-associated pain to examine its analgesic efficacy and safety. At 13 medical institutions in Japan, we conducted a phase II, double-blind, placebo-controlled, randomized trial of intravenous fosphenytoin in Japanese inpatients with acute zoster-associated pain for whom nonopioid analgesics had shown an insufficient analgesic effect. The patients were randomly assigned (1:1:1) to receive a single intravenous dose of fosphenytoin at 18 mg/kg (high dose), a single intravenous dose of fosphenytoin at 12 mg/kg (low dose), or placebo. The primary endpoint was the mean change per hour (slope) in the numerical rating scale score from the baseline score until 120 min after dosing. Seventeen patients were randomly assigned to the low-dose fosphenytoin group (n = 6, median age 62.5 years, range 39-75 years), high-dose fosphenytoin group (n = 5, median age 69.0 years, range 22-75 years), and placebo group (n = 5, median age 52.0 years, range 38-72 years). One patient was excluded because of investigational drug dilution failure. This study was discontinued because of the influences of coronavirus disease 2019. The slope was significantly lower in the high- and low-dose fosphenytoin groups than in the placebo group (P < 0.001 and P = 0.016, respectively). Responsiveness to intravenous fosphenytoin (≥2-point reduction in the numerical rating scale score from baseline to 120 min after dosing) was inferred at plasma total phenytoin concentrations of 10-15 μg/mL. Treatment-emergent adverse events caused no safety concerns in the clinical setting and intravenous fosphenytoin was well tolerated. Intravenous fosphenytoin appears to be an effective and promising alternative treatment for acute zoster-associated pain. Trial Registration: ClinicalTrials.gov NCT04139330.

Varicella Zoster Virus-Specific Hyperimmunoglobulin in the Adjuvant Treatment of Immunocompromised Herpes Zoster Patients: A Case Series

INTRODUCTION

Immunocompromised patients are at increased risk for herpes zoster (HZ)-associated complications. Despite standard therapy with systemic antiviral drugs and analgesics, complications are frequently encountered, including generalization of lesions or persistent neuropathic pain, so-called post-herpetic neuralgia (PHN). Given the scarcity of literature and awareness of therapeutic options to improve patient outcomes, especially for vulnerable patient groups, here we describe a strategy based on early intensification of treatment with a varicella zoster virus-specific hyperimmunoglobulin (VZV-IgG), which is approved in the adjuvant treatment of HZ.

METHODS

For this case series, we selected four cases of HZ in patients with impaired immunity due to hemato-oncologic disease or immunosuppressive treatment who presented with either existing generalized lesions and/or severe pain or with other risk factors for a complicated HZ course such as PHN. They were considered to be representative examples of different patient profiles eligible for intensification of treatment by the addition of VZV-IgG to virostatic therapy.

CASE REPORT

All patients showed a rapid response to combined treatment with VZV-IgG and a virostatic agent. In two patients who had generalized lesions, the formation of new lesions ceased 1 day after VZV-IgG infusion. One patient, with mantle cell lymphoma, achieved complete healing of the lesions 9 days after diagnosis of HZ, a rare occurrence compared to similar cases or cohorts. A patient with HZ in the cervical region showed a good response after a single dose of VZV-IgG. None of the patients developed post-zoster-related complications. Combination therapy of a virostatic agent and VZV-IgG was well tolerated in these four cases.

CONCLUSION

This case series demonstrates highly satisfactory treatment effectiveness and tolerability for VZV-IgG in the adjuvant treatment of immunocompromised HZ patients and supports early intensification of HZ therapy in patients at high risk of severe disease progression.

Recent Advances in Molecular Mechanisms of Nucleoside Antivirals

The search for new drugs has been greatly accelerated by the emergence of new viruses and drug-resistant strains of known pathogens. Nucleoside analogues (NAs) are a prospective class of antivirals due to known safety profiles, which are important for rapid repurposing in the fight against emerging pathogens. Recent improvements in research methods have revealed new unexpected details in the mechanisms of action of NAs that can pave the way for new approaches for the further development of effective drugs. This review accounts advanced techniques in viral polymerase targeting, new viral and host enzyme targeting approaches, and prodrug-based strategies for the development of antiviral NAs.

Current Infections of the Orofacial Region: Treatment, Diagnosis, and Epidemiology

Undoubtedly, diagnosing and managing infections is one of the most challenging issues for orofacial clinicians. As a result of the diversity of symptoms, complicated behavior, and sometimes confusing nature of these conditions, it has become increasingly difficult to diagnose and treat them. It also highlights the need to gain a deeper insight into the orofacial microbiome as we try to improve our understanding of it. In addition to changes in patients' lifestyles, such as changes in diet, smoking habits, sexual practices, immunosuppressive conditions, and occupational exposures, there have been changes in patients' lifestyles that complicate the issue. Recent years have seen the development of new infection treatments due to the increased knowledge about the biology and physiology of infections. This review aimed to provide a comprehensive overview of the types of infections in the mouth, including the types that viruses, fungi, or bacteria may cause. It is important to note that we searched the published literature in the Scopus, Medline, Google Scholar, and Cochran databases from 2010 to 2021 using the following keywords: "Orofacial/Oral Infections," "Viral/Fungal/Bacterial Infections", "Oral Microbiota" And "Oral Microflora" without limiting our search to languages and study designs. According to the evidence, the most common infections in the clinic include herpes simplex virus, human papillomavirus, Candida albicans, Aspergillus, Actinomycosis, and Streptococcus mutans. The purpose of this study is to review the new findings on characteristics, epidemiology, risk factors, clinical manifestations, diagnosis, and new treatment for these types of infectious diseases.

Current scenario and future applicability of antivirals against herpes zoster

Herpes zoster (HZ) is a common disease in the aging population and immunocompromised individuals, with a lifetime risk of 20%-30% that increases with age. HZ is caused by reactivation of the varicella-zoster virus (VZV), which remains latent in the spinal dorsal root ganglia and cranial sensory ganglia after resolution of the primary VZV infection. The main focus of HZ management is rapid recovery from VZV infection as well as the reduction and prevention of zoster-associated pain (ZAP) and postherpetic neuralgia (PHN). The use of antivirals against VZV is essential in the treatment of HZ. However, limited antivirals are only licensed clinically for the treatment of HZ, including acyclovir, valacyclovir, famciclovir, brivudine, and amenamevir. Fortunately, some new antivirals against different types of Herpesviridae have been investigated and suggested as novel drugs against VZV. Therefore, this review focuses on discussing the difference in efficacy and safety in the currently licensed antivirals for the treatment of HZ, the applicability of future novel antivirals against VZV, and the preventive or therapeutic effects of these antivirals on ZAP or PHN.

Comparing Prodrugs with Acyclovir for Treating Postherpetic Neuralgia among Herpes Zoster Patients: A Systematic Review and Meta-Analysis

Postherpetic neuralgia (PHN) is a common, painful, and long-term complication of herpes zoster (HZ). PHN increases the demand for healthcare services and, previous studies showed that patients who received antiviral agents were less likely to develop PHN. The objective of this study was to compare the efficacy of prodrugs and acyclovir in treating PHN among patients with HZ. The search included the PubMed, Medline, Embase, and Cochrane Center of Register of Controlled Trails databases through February 2022. Clinical trials and randomized controlled trials (RCTs) involving antiviral agent intervention for HZ patients diagnosed with PHN were eligible for inclusion. A meta-analysis was conducted to calculate pooled risk ratios (RRs) with 95% confidence intervals (CIs) with a fix-effect model. Five RCTs with 1147 HZ patients met our eligibility criteria. Our meta-analysis found that there was a significantly lower risk of PHN for members of the prodrugs group (famciclovir and valaciclovir) compared with those who received acyclovir (RR = 0.86, 95%, CI: 0.75 to 0.98, p = 0.03). The review of studies indicated that the efficacy of prodrugs was better than acyclovir for reliving PHN.

FV-100 for the Treatment of Varicella-Virus (VZV) Infections: Quo Vadis?

The bicyclic nucleoside analogue (BCNA) Cf1743 and its orally bioavailable prodrug FV-100 have unique potential as varicella-zoster virus (VZV) inhibitors to treat herpes zoster (shingles) and the therewith associated pain, including post-herpetic neuralgia (PHN). The anti-VZV activity of Cf1743 depends on a specific phosphorylation by the VZV-encoded thymidine kinase (TK). The target of antiviral action is assumed to be the viral DNA polymerase (or DNA synthesis in the virus-infected cells).

Pharmacological and non-pharmacological strategies for preventing postherpetic neuralgia: a systematic review and network meta-analysis

Background

Postherpetic neuralgia (PHN) is a refractory complication of herpes zoster (HZ). To prevent PHN, various strategies have been aggressively adopted. However, the efficacy of these strategies remains controversial. Therefore, we aimed to estimate the relative efficacy of various strategies used in clinical practice for preventing PHN using a network meta-analysis (NMA).

Methods

We performed a systematic and comprehensive search to identify all randomized controlled trials. The primary outcome was the incidence of PHN at 3 months after acute HZ. We performed both frequentist and Bayesian NMA and used the surface under the cumulative ranking curve (SUCRA) values to rank the interventions evaluated.

Results

In total, 39 studies were included in the systematic review and NMA. According to the SUCRA value, the incidence of PHN was lower in the order of continuous epidural block with local anesthetics and steroids (EPI-LSE), antiviral agents with subcutaneous injection of local anesthetics and steroids (AV + sLS), antiviral agents with intracutaenous injection of local anesthetics and steroids (AV + iLS) at 3 months after acute HZ. EPI-LSE, AV + sLS and AV + iLS were also effective in preventing PHN at 1 month after acute HZ. And paravertebral block combined with antiviral and antiepileptic agents was effective in preventing PHN at 1, 3, and 6 months.

Conclusions

The continuous epidural block with local anesthetics and steroid, antiviral agents with intracutaneous or subcutaneous injection of local anesthetics and a steroid, and paravertebral block combined with antiviral and antiepileptic agents are effective in preventing PHN.

Herpes Zoster (Shingles) Patient-Centered Wound Outcomes: A Literature Review

GENERAL PURPOSE

To present a comprehensive review of patient-centered outcomes of topical or systemic interventions applied to those with shingles or postherpetic neuralgia to inform clinical practice and identify related research needs.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will be able to:1. Explain the importance of early diagnosis and treatment of herpes zoster (HZ).2. Identify interventions that have resulted in documented improvement of validated patient-centered outcomes in patients with HZ or postherpetic neuralgia.3. Recognize the average per patient medical costs of HZ in the US.

Advances and Perspectives in the Management of Varicella-Zoster Virus Infections

Varicella-zoster virus (VZV), a common and ubiquitous human-restricted pathogen, causes a primary infection (varicella or chickenpox) followed by establishment of latency in sensory ganglia. The virus can reactivate, causing herpes zoster (HZ, shingles) and leading to significant morbidity but rarely mortality, although in immunocompromised hosts, VZV can cause severe disseminated and occasionally fatal disease. We discuss VZV diseases and the decrease in their incidence due to the introduction of live-attenuated vaccines to prevent varicella or HZ. We also focus on acyclovir, valacyclovir, and famciclovir (FDA approved drugs to treat VZV infections), brivudine (used in some European countries) and amenamevir (a helicase-primase inhibitor, approved in Japan) that augur the beginning of a new era of anti-VZV therapy. Valnivudine hydrochloride (FV-100) and valomaciclovir stearate (in advanced stage of development) and several new molecules potentially good as anti-VZV candidates described during the last year are examined. We reflect on the role of antiviral agents in the treatment of VZV-associated diseases, as a large percentage of the at-risk population is not immunized, and on the limitations of currently FDA-approved anti-VZV drugs. Their low efficacy in controlling HZ pain and post-herpetic neuralgia development, and the need of multiple dosing regimens requiring daily dose adaptation for patients with renal failure urges the development of novel anti-VZV drugs.

Herpes Zoster in the Older Adult

Herpes zoster (HZ) is the result of reactivation of latent varicella zoster virus (VZV) and occurs most frequently in older adults. Classically, HZ presents as a unilateral, selflimited, dermatomal rash. Postherpetic neuralgia (PHN) is a common sequela, presenting as severe pain that persists after the rash has resolved. In the elderly, PHN can be debilitating and requires a prompt diagnosis, treatment with antivirals, and adequate pain control. A longer-term pain management strategy is required if PHN occurs. A modestly effective vaccine exists and is recommended for older individuals.

Post-herpetic neuralgia - a review of current management and future directions

Post-herpetic neuralgia (PHN) is common and treatment is often suboptimal with less than half of patients achieving adequate 50% pain relief. As an area of unmet clinical need and as an archetype of neuropathic pain, it deserves the attention of clinicians and researchers. Areas covered: This review summarises the epidemiology, pathophysiology, risk factors and clinical features of varicella infection. It describes the current and possible future management strategies for preventing varicella infection and reactivation and for treating PHN. Expert opinion: A highly successful Varicella Zoster (VZV) vaccine has not been universally adopted due to fears that it may increase Herpes Zoster (HZ) incidence - and thus PHN - in older, unvaccinated generations. This is a controversial theory but advances in the efficacy of vaccines against HZ may allay these fears and encourage more widespread adoption of the VZV vaccine. Treatment of PHN, as for any neuropathic pain, must be multidisciplinary and multimodal. Advances in sensory phenotyping technology and genomics may allow more individualised treatment. Traditional research methodologies are ill-suited to assess the kind of complex interventions that are necessary to achieve better clinical outcomes in this challenging field.

FV-100 versus valacyclovir for the prevention of post-herpetic neuralgia and the treatment of acute herpes zoster-associated pain: A randomized-controlled trial

This prospective, parallel-group, randomized, double-blind, multicenter study compared the efficacy and safety of FV-100 with valacyclovir for reducing pain associated with acute herpes zoster (HZ). Patients, ≥50 years of age, diagnosed with HZ within 72 h of lesion appearance who had HZ-associated pain, were randomized 1:1:1 to a 7-day course of either FV-100 200 mg QD (n = 117), FV-100 400 mg QD (n = 116), or valacyclovir 1000 mg TID (n =117). Efficacy was evaluated on the basis of the burden of illness (BOI; Zoster Brief Pain Inventory scores); incidence and duration of clinically significant pain (CSP); pain scores; incidence and severity of post-herpetic neuralgia (PHN); and times to full lesion crusting and to lesion healing. Safety was evaluated on the basis of adverse event (AE)/SAE profiles, changes in laboratory and vital signs values, and results of electrocardiograms. The burden of illness scores for pain through 30 days were 114.5, 110.3, and 118.0 for FV-100 200 mg, FV-100 400 mg, and valacyclovir 3000 mg, respectively. The incidences of PHN at 90 days for FV-100 200 mg, FV-100 400 mg, and valacyclovir 3000 mg were 17.8%, 12.4%, and 20.2%, respectively. Adverse event and SAE profiles of the two FV-100 and the valacyclovir groups were similar and no untoward signals or trends were evident. These results demonstrate a potential for FV-100 as an antiviral for the treatment of shingles that could both reduce the pain burden of the acute episode and reduce the incidence of PHN compared with available treatments.