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. Unlike most antibiotics, antiviral drugs do not destroy their target pathogen; instead they inhibit its development.
They do this by being able to enter the cells infected with virus, interfere with viral nucleic acid synthesis and/or regulation, some agent interfere with virus ability to bind with cell while others stimulate the body’s immune system.
How They Were Discovered
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).
First experimental antivirals were developed in the 1960s, mostly to deal with herpes viruses, and were found using traditional trial-and-error drug discovery methods.
Only in the 1980s, when the full genetic sequences of viruses began to be unraveled, did researchers begin to learn how viruses worked in detail, and exactly what chemicals were needed to thwart their reproductive cycle.
Few drugs are selective enough to prevent viral replication without injury to the infected host cells. Therapy for viral diseases is further complicated by the fact that the clinical symptoms appear late in the course of the disease, at a time when most of the virus particles have replicated.
What are antiviral drugs used to treat?
Antiviral medications help the body fight off harmful viruses. The drugs can ease symptoms and shorten the length of a viral infection. Antivirals also lower the risk of getting or spreading viruses that cause herpes and HIV. One approved antiviral treats the coronavirus that causes COVID-19
What are the side effects of antiviral drugs?
Like all medicines, antiviral drug can cause side effects, although not everyone gets them. Common side effects include: nausea and vomiting. diarrhoea and stomach ache.
Less common side effects include:
• sleeping difficulties.
• skin reactions.
• heart rhythm abnormalities.
• abnormal behavior.
What if I get side effects?
You should tell your pharmacist or doctor straight away if you are concerned that any of the side effects get serious.
Antiviral drugs Safety
Studies have shown that Neuraminidase inhibitors are generally well tolerated and have a favorable risk–benefit profile. However, serious adverse events reported in postmarketing use in individuals who took oseltamivir include skin reactions, neuropsychiatric events, and pediatric deaths (the latter two largely reported from use in Japan).
Gastrointestinal disturbances are reported in about 10 percent of users. Adverse events experienced by people who took zanamivir include headaches, gastrointestinal problems, respiratory problems, dizziness, and musculoskeletal symptoms. Postmarketing adverse events also include allergic, cardiac, neurologic, and skin reactions, as well as bronchospasm.
Oseltamivir and zanamivir have been on the market for years and more is known about their safety profiles now than at the time of approval. However, wide-scale and prolonged use of these drugs in populations who were not well studied may lead to the recognition of rare but serious adverse events. Moreover, with the widespread use anticipated during a pandemic, reports of possible adverse events will be much more likely and will need to be rapidly evaluated. A telling example is found in reports of neuropsychiatric adverse events from Japan where oseltamivir is used much more widely than in the United States in treating seasonal influenza. Despite two careful reviews by Food and Drug Administration (FDA) staff and FDA advisory committees, it has not been possible to date to determine if the neuropsychiatric events are causally associated with oseltamivir.
The use of Whoonga a drug cocktail in South Africa that contains illicit drugs and HIV antiretroviral (ARV) medication may adversely impact adherence to HIV treatment and may have the potential to generate ARV resistance.