Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Antiviral drugs are one class of antimicrobials, a larger group which also includes antibiotic, antifungal and antiparasitic drugs, or antiviral drugs based on monoclonal antibodies. Most antivirals are considered relatively harmless to the host, and therefore can be used to treat infections. They should be distinguished from virucides, which are not medication but deactivate or destroy virus particles, either inside or outside the body. Natural virucides are produced by some plants such as eucalyptus and Australian tea trees.
Ribavirin, also known as tribavirin, is an antiviral medication used to treat RSV infection, hepatitis C and some viral hemorrhagic fevers. For hepatitis C, it is used in combination with other medications such as simeprevir, sofosbuvir, peginterferon alfa-2b or peginterferon alfa-2a. Among the viral hemorrhagic fevers it is used for Lassa fever, Crimean–Congo hemorrhagic fever, and Hantavirus infection but should not be used for Ebola or Marburg infections. Ribavirin is taken by mouth or inhaled.
Aciclovir (ACV), also known as acyclovir, is an antiviral medication. It is primarily used for the treatment of herpes simplex virus infections, chickenpox, and shingles. Other uses include prevention of cytomegalovirus infections following transplant and severe complications of Epstein–Barr virus infection. It can be taken by mouth, applied as a cream, or injected.
ATC code J05Antivirals for systemic use is a therapeutic subgroup of the Anatomical Therapeutic Chemical Classification System, a system of alphanumeric codes developed by the World Health Organization (WHO) for the classification of drugs and other medical products. Subgroup J05 is part of the anatomical group J Antiinfectives for systemic use.
Zanamivir is a medication used to treat and prevent influenza caused by influenza A and influenza B viruses. It is a neuraminidase inhibitor and was developed by the Australian biotech firm Biota Holdings. It was licensed to Glaxo in 1990 and approved in the US in 1999, only for use as a treatment for influenza. In 2006, it was approved for prevention of influenza A and B. Zanamivir was the first neuraminidase inhibitor commercially developed. It is marketed by GlaxoSmithKline under the trade name Relenza as a powder for oral inhalation.
Oseltamivir, sold under the brand name Tamiflu, is an antiviral medication used to treat and prevent influenza A and influenza B, viruses that cause the flu. Many medical organizations recommend it in people who have complications or are at high risk of complications within 48 hours of first symptoms of infection. They recommend it to prevent infection in those at high risk, but not the general population. The Centers for Disease Control and Prevention (CDC) recommends that clinicians use their discretion to treat those at lower risk who present within 48 hours of first symptoms of infection. It is taken by mouth, either as a pill or liquid.
Amantadine, sold under the brand name Gocovri among others, is a medication used to treat dyskinesia associated with parkinsonism and influenza caused by type A influenzavirus, though its use for the latter is no longer recommended due to widespread drug resistance. It acts as a nicotinic antagonist, dopamine agonist, and noncompetitive NMDA antagonist. The antiviral mechanism of action is antagonism of the influenzavirus A M2 proton channel, which prevents endosomal escape.
ViroPharma Incorporated was a pharmaceutical company that developed and sold drugs that addressed serious diseases treated by physician specialists and in hospital settings. The company focused on product development activities on viruses and human disease, including those caused by cytomegalovirus (CMV) and hepatitis C virus (HCV) infections. It was purchased by Shire in 2013, with Shire paying around $4.2 billion for the company in a deal that was finalized in January 2014. ViroPharma was a member of the NASDAQ Biotechnology Index and the S&P 600.
Treatments for influenza include a range of medications and therapies that are used in response to disease influenza. Treatments may either directly target the influenza virus itself; or instead they may just offer relief to symptoms of the disease, while the body's own immune system works to recover from infection.
Foscarnet (phosphonomethanoic acid), known by its brand name Foscavir, is an antiviral medication which is primarily used to treat viral infections involving the Herpesviridae family. It is classified as a pyrophosphate analog DNA polymerase inhibitor. Foscarnet is the conjugate base of a chemical compound with the formula HO2CPO3H2 (Trisodium phosphonoformate).
Umifenovir, sold under the brand name Arbidol, is an antiviral medication for the treatment of influenza and COVID infections used in Russia and China. The drug is manufactured by Pharmstandard. It is not approved by the U.S. Food and Drug Administration (FDA) for the treatment or prevention of influenza.
BioCryst Pharmaceuticals, Inc. is an American pharmaceutical company headquartered in Durham, North Carolina. The company is a late stage biotech company that focuses on oral drugs for rare and serious diseases. BioCryst's antiviral drug peramivir (Rapivab) was approved by FDA in December 2014. It has also been approved in Japan, Korea, and China.
Favipiravir, sold under the brand name Avigan among others, is an antiviral medication used to treat influenza in Japan. It is also being studied to treat a number of other viral infections, including SARS-CoV-2. Like the experimental antiviral drugs T-1105 and T-1106, it is a pyrazinecarboxamide derivative.
JK-05 is a broad-spectrum antiviral drug developed by the Chinese company Sihuan Pharmaceutical along with the Chinese Academy of Military Medical Sciences. It is reported to act as an inhibitor of the viral enzyme RNA polymerase which is essential for viral replication. In tests on mice, JK-05 was claimed to show efficacy against a range of RNA viruses, including influenza, Ebola virus and yellow fever, as well as several arenaviruses and bunyaviruses. The chemical structure of JK-05 has not been disclosed as of October 2014, but it is claimed to be a small molecule drug with a comparatively simple structure, which should be readily amenable to synthesis scale-up for mass production if testing is successful. The drug is however admitted to be similar to the Japanese anti-influenza drug favipiravir, developed by Fujifilm Holdings Corp, which has been used effectively to treat patients with Ebola. In addition, WHO committee members mentioned that the drug is a copy product of favipiravir, because patents of favipiravir were already registered in 2006 in China. The drug has been given preliminary approval by the Chinese authorities to be available for Chinese health workers involved in combating the 2014 West African Ebola outbreak, or if Ebola were to spread into mainland China. Several other Chinese developed antiviral drugs with anti-Ebola activity have also been disclosed, but have not progressed so far through development as JK-05.
There is no cure or specific treatment for the Ebola virus disease that is currently approved for market, although various experimental treatments are being developed. For past and current Ebola epidemics, treatment has been primarily supportive in nature.
Riamilovir is a broad-spectrum antiviral drug developed in Russia through a joint effort of Ural Federal University, Russian Academy of Sciences, Ural Center for Biopharma Technologies and Medsintez Pharmaceutical. It has a novel triazolotriazine core, which represents a new structural class of non-nucleoside antiviral drugs.
NITD008 is an antiviral drug classified as an adenosine analog. It was developed as a potential treatment for flavivirus infections and shows broad spectrum antiviral activity against many related viruses such as dengue virus, West Nile virus, yellow fever virus, Powassan virus, hepatitis C virus, Kyasanur Forest disease virus, Omsk hemorrhagic fever virus, and Zika virus. However, NITD008 proved too toxic in pre-clinical animal testing to be suitable for human trials, but it continues to be used in research to find improved treatments for emerging viral diseases.
Broad-spectrum antivirals (BSAs) are a class of molecules or compounds, which inhibit the replication of a broad range of viruses. BSAs could be divided into experimental and investigational agents, and approved drugs. BSAs work by inhibiting viral proteins or by targeting host cell factors and processes exploited by different viruses during infection. As of 2021, there are 150 known BSAs in varying stages of development, effective against 78 human viruses. BSAs are potential candidates for treatment of emerging and re-emerging viruses, such as ebola, marburg, and SARS-CoV-2. Many BSAs show antiviral activity against other viruses than originally investigated. Efforts in drug repurposing for SARS-CoV-2 is currently underway. A database of BSAs and viruses they inhibit could be found here.
Molnupiravir, sold under the brand name Lagevrio, is an antiviral medication that inhibits the replication of certain RNA viruses. It is used to treat COVID-19 in those infected by SARS-CoV-2. It is taken by mouth.
Nirmatrelvir/ritonavir, sold under the brand name Paxlovid, is a co-packaged medication used as a treatment for COVID‑19. It contains the antiviral medications nirmatrelvir and ritonavir and was developed by Pfizer. Nirmatrelvir is a SARS-CoV-2 main protease inhibitor while ritonavir is an HIV-1 protease inhibitor and strong CYP3A inhibitor.
