Notes
Anti-Viral Drugs: HSV, CMV, & Influenza
Sections
Herpesvirus Antivirals
Acyclovir
Administered Intravenously, orally, or topically.
Treats:
Herpes virus 1 and Herpes Virus 2
Varicella-zoster virus (the cause of chickenpox)
Herpes-zoster virus (the reactivated VZV, and is the cause of shingles)
Mechanism:
Acyclovir is a guanosine analogue; it inserts acyclo-GTP (acyclovir triphosphate, a derivative of acyclovir) into actively replicating viral chains and stopping their growth
It is activated by virus-encoded thymidine kinase
Adverse Effects:
At high doses, it can be nephrotoxic and neurotoxic.
Valacyclovir* & *Famciclovir
Valcyclovir is a prodrug of acyclovir; famciclovir is a prodrug of penciclovir.
Administered orally.
Treats:
Nerve pain associated with herpes zoster infection.
Herpes Simplex Virus infections.
Mechanism:
Mechanisms of action are similar to acyclovir.
Adverse Effects:
Headaches, dizziness, GI upset, and diarrhea.
Ganciclovir
Valganiciclovir is its prodrug.
Administered intravenously or orally.
Treats:
Cytomegalovirus infections (retinitis, pneumonia, and esophagitis)
May be used as prophylaxis in In transplant recipients
Can be used, but is not preferred, for:
Herpes Simplex Virus, Herpes Zoster Virus, Epstein-Barr Virus, Human Herpes Virus 6.
Mechanism:
Ganiciclovir is a guanosine analogue that inhibits viral DNA synthesis.
Adverse Effects:
More toxic than acyclovir, and is associated with bone marrow suppression and, as a result, leukopenia and thrombocytopenia
Foscarnet
Administered intravenously.
Treats:
Cytomegalovirus infections, specifically those that are Ganciclovir-resistant and/or present in AIDS patients.
Acyclovir-resistant Herpes Simplex Virus and Varicella-Zoster virus.
Human Herpes Virus 6.
Mechanism:
Foscarnet is a pyrophosphate analogue that inhibits viral DNA replication
Adverse Effects:
Potentially nephrotoxic; associated in anemia in AIDS patients, as well as serum electrolyte changes (such as hypocalcemia and hypomagnesemia).
Fomivirsen
Administered via eye injection.
Treats:
Cytomegalovirus retinitis, particularly in AIDS patients.
Mechanism:
Blocks Cytomegalovirus replication
Adverse Effects:
Associated with increased ocular inflammation and pressure.
Trifluridine
Administered via eye dropper.
Treats:
Herpes Simplex Virus cornea infections.
Mechanism:
Thymidine nucleoside analogue that inserts into viral DNA and blocks replication
Adverse Effects:
Very toxic if administered intravenously, which is why it is used for eye infections.
Influenza Antivirals
Amantadine and Rimantadine
Administered orally.
Treats:
Influenza A; high resistance in the United States.
These drugs may also be used to treat Parkinson's disease.
Mechanisms:
Prevent viral uncoating.
Adverse Effects:
Anxiety and confusion, particularly in the elderly, who appear more likely to experience these effects when given Amantadine.
Dry mouth and urine retention are also reported, due to anticholinergic effects.
Teratogenic: Do not give these drugs to pregnant people
Oseltamivir
Administered orally.
Treats:
Influenza A and Influenza B; may be given as prophylaxis.
Mechanisms:
Inhibits neuraminidase, which blocks release of the virus from host cells.
Adverse Effects:
Nausea and vomiting.
Zanamivir
Administered as a powder that is orally inhaled.
Treats:*
Influenza A and B; H1N1 "Swine Flu"
Mechanisms:
Inhibits neuraminidase.
Adverse Effects:
Neutropenia, gastrointestinal upset, nasal congestion/runny nose, cough, and other effects that are similar to symptoms of the flu.
Be aware that some authors express concerns about administering a powder drug to patients with pulmonary disease.
Peravimir
Administered intravenously.
Treats:
Influenza A and B
Mechanisms:
Inhibits neuraminidase
Adverse Effects:
Associated with diarrhea, nausea, vomiting, and neutropenia.
Be aware that intertextual variation and differences in prescribing practices exist.
References
Bhatia, Harmeet Kaur, Harmanjit Singh, Nipunjot Grewal, and Navreet Kaur Natt. "Sofosbuvir: A Novel Treatment Option for Chronic Hepatitis C Infection." Journal of Pharmacology & Pharmacotherapeutics 5, no. 4 (2014): 278–84. https://doi.org/10.4103/0976-500X.142464.
Connell, Bridgette J., and Hugues Lortat-Jacob. "Human Immunodeficiency Virus and Heparan Sulfate: From Attachment to Entry Inhibition." Frontiers in Immunology 4 (November 20, 2013). https://doi.org/10.3389/fimmu.2013.00385.
Dogra, Pranay, Emily B. Martin, Angela Williams, Raphael L. Richardson, James S. Foster, Nicole Hackenback, Stephen J. Kennel, Tim E. Sparer, and Jonathan S. Wall. "Novel Heparan Sulfate-Binding Peptides for Blocking Herpesvirus Entry." PLOS ONE 10, no. 5 (May 18, 2015): e0126239. https://doi.org/10.1371/journal.pone.0126239.
Dyer, A P, B W Banfield, D Martindale, D M Spannier, and F Tufaro. "Dextran Sulfate Can Act as an Artificial Receptor to Mediate a Type-Specific Herpes Simplex Virus Infection via Glycoprotein B." Journal of Virology 71, no. 1 (January 1997): 191–98.
"Ganciclovir and Valganciclovir: An Overview - UpToDate." Accessed June 18, 2018. https://www-uptodate-com.proxy.medlib.uits.iu.edu/contents/ganciclovir-and-valganciclovir-an-overview?search=ganciclovir&source=search_result&selectedTitle=2~105&usage_type=default&display_rank=5.
"HHV-6 & Encephalitis | HHV-6 Foundation | HHV-6 Disease Information for Patients, Clinicians, and Researchers | Apply for a Grant." Accessed June 20, 2018. https://hhv-6foundation.org/associated-conditions/hhv-6-and-encephalitis.
"Neuraminidase Inhibitors for Treatment of Influenza A and B Infections." Accessed June 18, 2018. https://www.cdc.gov/Mmwr/preview/mmwrhtml/rr4814a1.htm.
Images:
"Cytomegalovirus Retinitis." Wikipedia, June 16, 2018. https://en.wikipedia.org/w/index.php?title=Cytomegalovirus_retinitis&oldid=846108194.
"09G0036_lores.Jpg (700×482)." Accessed June 18, 2018. https://phil.cdc.gov/PHIL_Images/06011999/00016/09G0036_lores.jpg.