HWN Suggests

Developing antiviral drugs is not easy – here’s why

The reason there are few effective broad-spectrum antivirals is that viruses are much more diverse than bacteria, including in how they store their genetic information (some in the form of DNA and some as RNA). Unlike bacteria, viruses have fewer of their own protein building blocks that can be targeted with drugs.

For a drug to work, it has to reach its target. This is particularly difficult with viruses because they replicate inside human cells by hijacking our cellular machinery. The drug needs to get inside these infected cells and act on processes that are essential for the normal functioning of the human body. Unsurprisingly, this often results in collateral damage to human…

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 Fighting Viruses: How Do Antivirals Work?

Rather than killing a virus directly, antivirals usually suppress the virus's ability to infect and multiply in your cells. These drugs often work by inhibiting molecular interactions and functions needed by the virus to produce new copies of itself. The way a drug produces its therapeutic effect is called its mechanism of action. Antivirals are often delivered in combinations that have different mechanisms of action. This helps to prevent the emergence of mutated drug-resistant viral strains that can bypass the effects of a single drug. For example, combination antiviral therapy is now the standard of care in HIV and hepatitis C virus infections. It is highly desirable to develop multiple antivirals whenever possible.

Articles of Interest

In the Next Pandemic Antiviral Drugs Could Be Key, But Are They Ready?

Scientists say another pandemic is likely and have even identified several viruses that could be a threat. But there are currently few approved drugs or treatments for these potential threats, nor is there much in the pipeline.

Meet the woman who gave the world antiviral drugs

Fifty years ago, few scientists believed a drug could fight viruses with low side effects. Then Gertrude Elion showed the doubters "what I could do on my own."

Approved Antiviral Drugs over the Past 50 Years

Since the first antiviral drug, idoxuridine, was approved in 1963, 90 antiviral drugs categorized into 13 functional groups have been formally approved for the treatment of the following 9 human infectious diseases...

COVID: antiviral drugs are a vital weapon – but misusing them could backfire

The “living with COVID” strategy being pursued by many countries relies heavily on two key pillars. First, that vaccines continue to protect most people from severe disease. And second, that where they don’t, people will receive antiviral treatments. But are the antivirals currently available sufficiently effective, accessible and durable?

For an antiviral researcher, Covid brings a flood of attention — and opportunity

Researchers seeking to develop antivirals have long warned that a new virus could wreak disaster around the globe and sought funding for their work, only to be largely ignored. Now, the Covid-19 pandemic has unleashed a flood of new money for studies on antivirals, with interest surging from both the government and industry.

George Hitchings and Gertrude Elion

George Hitchings (1905–1998) and Gertrude Elion (1918–1999) diverged from this traditional path by deliberately designing new molecules with specific molecular structures, using what today is termed rational drug design. Using this effective technique they designed compounds that would interfere with the natural production of DNA in cells and so interrupt cell growth.

History and progress of antiviral drugs: From acyclovir to direct-acting antiviral agents (DAAs) for Hepatitis C

The development of antiviral drugs is a very complex process. Currently, around 50 drugs have been approved for human use against viruses such as HSV, HIV-1, the cytomegalo virus, the influenza virus, HBV and HCV. Advancements in this area have been achieved through efforts and technical breakthroughs in different scientific fields. The improvement in the treatment of HCV infection is a good example of what is needed for efficient antiviral therapy

Seven classes of antiviral agents

The viral epidemics and pandemics have stimulated the development of known and the discovery of novel antiviral agents. About a hundred mono- and combination antiviral drugs have been already approved, whereas thousands are in development.

What are antiviral drugs and how do they work?

Antiviral medications have been around since the 1960s in the form of pills, intravenous solutions, ointments and even eye drops. They exist for only a handful of viruses, including H.I.V., the herpes simplex viruses, hepatitis B and C viruses, influenza A and B, and now the coronavirus.

Why are there so many drugs to kill bacteria, but so few to tackle viruses?

Why are there so few antivirals? The answer boils down to biology, and specifically the fact viruses use our own cells to multiply. This makes it hard to kill viruses without killing our own cells in the process.

Resources

Ebola

The recommendation follows review and analysis of clinical trials for the monoclonal antibodies mAb114 (known as Ansuvimab or Ebanga) and REGN-EB3 (Inmazeb), which have demonstrated clear benefits for people who have tested positive for Ebola, which is often fatal.

Hep B

There are currently 7 approved drugs in the United States for adults living with chronic hepatitis B infection. These include 5 types of antiviral drugs that are taken as a pill once a day for 1 year or longer. And there are 2 types of immune modulator drugs called “interferon” that are given as an injection for 6 months to 1 year.

Hep C

Antiviral medicine eliminates hepatitis C in 97% of patients, but Stanford Medicine researchers and colleagues find that many don’t receive the treatment.

Herpes Simplex

Acyclovir is an agent used to treat infections caused by the herpes simplex virus (HSV). It is FDA approved to treat genital herpes and HSV encephalitis. Non-FDA-approved indications are mucocutaneous HSV, herpes zoster (shingles), and varicella-zoster (chickenpox). Acyclovir is the first-line treatment for HSV encephalitis.

HIV

Recent advances in treatment and prevention of HIV warrant updated recommendations to guide optimal practice.

Physiopedia

The emergence of antivirals is the product of a our newly acquired knowledge of the genetic and molecular function of organisms letting us better understand the structure and function of viruses, major advances in the techniques for finding new drugs, and the pressure placed on the medical profession to deal with the human immunodeficiency virus (HIV), the cause of acquired immunodeficiency syndrome (AIDS).