penciclovir
Regulatory sources consulted
Approved indications
- Topical treatment of recurrent herpes labialis in adults and adolescents aged 12 years and older.
Contraindications
Absolute
- Hypersensitivity to penciclovir or cream components.
Clinical warnings
- Major warning · Do not use in the eyes, mouth, nose, or other mucosa. Avoid eye contact. — FDA label, set_id 5d95b934-2ba6-41b9-928f-6d2ce12f93f5
Adverse events
Common (≥1%)
Application-site reaction
Pregnancy and lactation
Systemic exposure after topical use is minimal; use during pregnancy or breastfeeding only if benefit justifies risk according to the label.
Recent literature (PubMed)
Antiviral drug resistance in herpes simplex virus 1 and 2 (HSV-1 and 2) is a significant clinical challenge, particularly in immunocompromised patients. Drug susceptibility testing (DST) aids clinical management and can be conducted through genotypic (partial genome sequencing) or phenotypic (cell culture) methods. Both have inherent limitations: genotypic DST is limited by outdated datasets lacking information on new helicase-primase inhibitors and corresponding phenotypic data as well as sparse clinical correlations. Phenotypic DST is mainly hampered by a lack of standardization and timely results. This study aims to compile an up-to-date and comprehensive HSV drug resistance dataset encompassing all reported drug resistance-associated mutations (DRMs), polymorphisms, and viral phenotypes. This study also aims to aggregate clinical conditions with available DST data. A PubMed search identified studies (January 2016-September 2024) on DRMs associated with resistance to aciclovir, penciclovir, brivudine, foscarnet, cidofovir, amenamevir, and pritelivir. Data from a previous HSV resistance dataset (pre-2016) were also included. In this review, we summarize novel mutations in the thymidine kinase, polymerase, and helicase-primase genes of HSV conferring resistance to antiviral drugs. Clinical information was available for 513 mutations. In 90% of these (461 cases), viral phenotype and clinical assessment were congruent. However, 10% of cases not responding to antiviral therapy showed phenotypically susceptible virus isolates. We present a framework for clinical and diagnostic management of cases with drug-resistant HSV infection. This dataset paves the way to harmonize reporting of DRMs for diagnostic labs and to accelerate genotypic DST interpretation through aggregated data. Ongoing large-scale data collection of genotypic, phenotypic, and clinical data is crucial for evidence-based management of HSV antiviral resistance and clinical guidelines.
This review article describes the current knowledge about the use of antiviral chemotherapeutics in avian species, such as farm poultry and companion birds. Specific therapeutics are described in alphabetical order including classic antiviral drugs, such as acyclovir, abacavir, adefovir, amantadine, didanosine, entecavir, ganciclovir, interferon, lamivudine, penciclovir, famciclovir, oseltamivir, ribavirin, and zidovudine, repurposed drugs, such as ivermectin and nitazoxanide, which were originally used as antiparasitic drugs, and some others substances showing antiviral activity, such as ampligen, azo derivates, docosanol, fluoroarabinosylpyrimidine nucleosides, and novel peptides. Most of them have only been used for research purposes and are not widely used in clinical practice because of a lack of essential pharmacokinetic and safety data. Suggested future research directions are also highlighted.
Introduction: Acyclovir has led to the development of successful systemic therapy for herpes simplex virus and varicella-zoster virus (VZV) infection, and the use of valacyclovir and famciclovir has improved treatment. Additionally, the use of a helicase-primase (HP) inhibitor (HPI), amenamevir, is changing the treatment of herpes zoster (HZ).Area covered: VZV infection is prevented by vaccines and is treated with antiviral agents. Acyclovir and penciclovir are phosphorylated by viral thymidine kinase and work as chain terminators. Improvements in the management of immunocompromised patients have reduced severe and prolonged immunosuppression and chronic VZV infection with acyclovir-resistant mutants has become rarer. The HP is involved in the initial step of DNA synthesis and amenamevir has novel mechanisms of action, efficacy to acyclovir-resistant mutants, and pharmacokinetic characteristics. The literature search for PUBMED was conducted on 10 April 2020 and updated on 4 November 2020.Expert opinion: Amenamevir has been used to treat HZ in Japan. Although the number of patients with VZV infection will decrease owing to the use of vaccines, the addition of HPI will improve treatment and treatment options for resistant viruses. The clinical use of HPIs in addition to current nucleoside analogs opens a new era of antiherpes therapy.
DNA is commonly known as the "molecule of life" because it holds the genetic instructions for all living organisms on Earth. The utilization of modified nucleosides holds the potential to transform the management of a wide range of human illnesses. Modified nucleosides and their role directly led to the 2023 Nobel prize. Acyclic nucleosides, due to their distinctive physiochemical and biological characteristics, rank among the most adaptable modified nucleosides in the field of medicinal chemistry. Acyclic nucleosides are more resistant to chemical and biological deterioration, and their adaptable acyclic structure makes it possible for them to interact with various enzymes. A phosphonate group, which is linked via an aliphatic functionality to a purine or a pyrimidine base, distinguishes acyclic nucleoside phosphonates (ANPs) from other nucleotide analogs. Acyclic nucleosides and their derivatives have demonstrated various biological activities such as anti-viral, anti-bacterial, anti-cancer, anti-microbial, etc. Ganciclovir, Famciclovir, and Penciclovir are the acyclic nucleoside-based drugs approved by FDA for the treatment of various diseases. Thus, acyclic nucleosides are extremely useful for generating a variety of unique bioactive chemicals. Their biological activities as well as selectivity is significantly influenced by the stereochemistry of the acyclic nucleosides because chiral acyclic nucleosides have drawn a lot of interest due to their intriguing biological functions and potential as medicines. For example, tenofovir's (R) enantiomer is roughly 50 times more potent against HIV than its (S) counterpart. We can confidently state, "The most promising developments are yet to come in the realm of acyclic nucleosides!" Herein, we have covered the most current developments in the field of chemical synthesis and therapeutic applications of acyclic nucleosides based upon our continued interest and activity in this field since mid-1990's.