Ever since World War II we have taken antibiotics for granted. Penicillin was the great game changer against bacterial infections. Antiviral drugs did not get the same attention. In fact, many health authorities doubted that there could ever be safe and effective antiviral drugs.
Zovirax (Acyclovir) for Herpes
An insider at Burroughs Wellcome (BW) informed us that the company was working on an antiviral medication against herpes simplex virus (HSV) infections. This virus causes both cold sores on the lips as well as genital sores.
There was a huge stigma associated with herpes during the early 80s. There were no FDA-sanctioned treatments. People really suffered. A diagnosis of genital herpes seemed like overwhelming burden.
We were excited to learn that BW was on to something that might work to speed healing from HSV infections. Although company insiders were convinced that they had impressive data, the FDA was skeptical. Experts there believed that drugs that could inhibit viral replication would be far too toxic for humans. Antiviral drugs against herpes seemed like a pipe dream to the bureacrats.
To many people’s surprise, though, acyclovir (Zovirax) improved healing time for cold sores. Toxicity was not an issue. The drug was surprisingly safe.
An Antiviral Lost to History:
Before acyclovir, the only antiviral drug the FDA had approved was amantadine (Symmetrel). This drug was given a green light to prevent Asian influenza in 1968.
It worked against type A flu viruses, but not against type B influenza. As a result, it has pretty much faded from the antiviral armamentarium. It is prescribed for Parkinson’s disease (PD), though.
A chance observation by a PD patient that her symptoms improved while she was taking the flu medicine led to clinical trials. The FDA eventually approved amantadine for Parkinson’s disease (Neurology, April 3, 2012).
FDA Approval for Antiviral Drugs vs. Herpes
Topical Zovirax received FDA approval in 1982. The pills went on the market in 1985.
Since then, other medications have become available to treat herpes infections. They include valacyclovir (Valtrex) and famciclovir (Famvir). There is now a clinical trial underway to determine if valacyclovir might help against Alzheimer’s disease (BMJ Open, Feb. 2020).
Antiviral Drugs vs. AIDS
In the early 1980s Acquired Immunodeficiency Syndrome (AIDS) became a terrifying epidemic. When scientists identified the human immunodeficiency virus (HIV) as the cause, the search was on to find antiviral medicines to treat this deadly disease.
Once again, the Burroughs Wellcome company led the way. It took an old drug off the shelf and repurposed AZT (azidothymidine) against HIV. The FDA approved it in record time in 1987.
The drug wasn’t perfect, but it did spur additional research and development. Today, there are over 40 HIV antiviral drugs and combinations. Although such medications do not cure the disease, they do control it. A diagnosis of AIDS is no longer a death sentence.
Antiviral Drugs vs. Hepatitis:
Hepatitis drugs are another success story. Medications like adefovir (Hepsera), entecavir (Baraclude), lamivudine (Epivir), telbivudine (Tyzeka) and tenofovir (Viread) have revolutionized the treatment of hepatitis B.
In addition, there are now more than 20 antiviral drugs or combinations to treat hepatitis C. Many cure the infection. These are among the great accomplishments of modern medicine.
Antiviral Drugs vs. the Coronavirus:
Now, the world is faced with an overwhelming pandemic. The novel coronavirus (SARS-CoV-2) causes a potentially deadly condition called COVID-19. Scientists all over the world are scrambling to find antiviral agents to combat this infection.
One of the more promising compounds is called remdesivir. It was developed by Gilead Sciences, a company that has built its reputation developing antiviral hepatitis drugs. Remdesivir is now in clinical trials and everyone is awaiting the results with great anticipation.
Two much older drugs are also capturing attention. Chloroquine (CQ) and hydroxychloroquine (HCQ) were developed to treat malaria during the 1940s. Malaria is caused by a blood parasite transmitted by mosquito bites, not by a virus. Nonetheless, researchers noted 30 years ago that these compounds had antiviral activity.
More recently scientists have found that these old drugs could be used against several coronavirus infections including SARS (severe acute respiratory syndrome) (Virology Journal, Aug. 22, 2005).
As a result of promising test tube experiments, clinicians are now investigating whether CQ or HCQ are effective against COVID-19. People all over the world holding are holding their breath hoping for success.
You can read about the latest developments in the drama to test hydroxychloroquine at this link.
The Latest on Hydroxychloroquine for COVID-19
The FDA just issued emergency use authorization for HCQ and CQ to treat the coronavirus. What’s the latest on hydroxychloroquine for COVID-19? New Data!
Have you ever taken antiviral drugs? Please share your story in the comment section below.