Viruses are tiny germs made of genetic material (DNA or RNA) inside a protein coating that cause common, mild illnesses such as the common cold or gastroenteritis, as well as severe, life-threatening diseases such as Ebola virus and HIV/AIDS. Some viral diseases that are common and/or significant in South Africa include influenza (“the flu”), coronaviruses (including COVID-19), Marburg virus, Epstein-Barr virus (mononucleosis or “mono”), herpes simplex virus, cytomegalovirus (CMV), human papillomavirus (genital or body warts), Hantavirus, Rift Valley Fever, rotavirus, norovirus (“stomach flu”), varicella (chicken pox, shingles), West Nile Virus, and Human Immunodeficiency Virus/ HIV (which causes AIDS). There are several antiviral medications available. It is important to remember that most antiviral medications do not cure viral infections but can help improve symptoms and decrease the duration of illness. In long-term viral infections, antivirals can help to control the infection and improve quality of life and lengthen life expectancy. Human immunodeficiency virus (HIV) is a clear example of this. Viruses need a host cell, meaning they must multiply inside a human or animal cell to remain infectious and cause disease. Antivirals work by blocking a virus’s entry into cells, interrupting the viral replication/ growth process, or enhancing the immune system to fight the virus. These medications can decrease the viral load/amount of virus in the body, help the virus to become inactive, and help reduce transmission of the virus to others. Examples of illnesses that antivirals are used to treat include HIV, Hepatitis B and C, influenza, genital herpes, human papillomavirus (warts), COVID-19, chicken pox, shingles, Ebola virus, and cytomegalovirus (CMV).
Medications used to treat viral diseases include antiviral medications, interferons, antibodies, and topical treatments for warts.
Influenza Antivirals can help shorten the duration and lessen the severity of the flu, and some can help prevent infection with the influenza virus. Not all people with the influenza virus will require treatment with antiviral medication, but it is recommended that anyone who is at a high risk of complications from the flu (people who are over the age of 65 or under age 2, with chronic health conditions- especially lung or heart conditions, and with weakened immune systems), and pregnant women receive treatment. For these medications to be effective, they must be started within 48 hours of the onset of symptoms. High-risk people who are in close contact with someone infected with influenza may also receive prophylactic (preventative) treatment with antivirals. The most used antivirals for influenza are called neuraminidase inhibitors. They block the action of an enzyme the flu virus uses to reproduce. Examples include oseltamivir and zanamivir.
COVID-19 Antivirals block the COVID-19 virus from entering cells and reproducing. These work best when started early in the course of the disease (within 5 days of symptom onset) and are recommended for use in patients who are at high risk of complications from COVID-19. There are two oral medications available: molnupiravir and nirmatrelvir/ritonavir, and one IV medication: remdesivir.
Antivirals for Herpes Viruses treat herpes simplex, which causes genital and oral herpes, as well as cytomegalovirus (CMV). These medications work by stopping viral DNA synthesis, which is essential for replication. Examples include acyclovir, valacyclovir, foscarnet, ganciclovir, valganciclovir, and famciclovir. These medications may also be used in the treatment of shingles and chicken pox caused by varicella viruses.
Hepatitis Antivirals treat chronic (long-term) Hepatitis B and C infections. They are not recommended in patients who initially have the virus, as sometimes the body can fight the virus on its own. They work by stopping viral DNA synthesis. Examples of these medications are entecavir, tenofovir, and sofosbuvir/velpatasvir.
HIV Treatment usually involves at least 2-3 different types of HIV antivirals (also called “antiretrovirals”) that work by acting on different stages of the HIV life cycle. This is because the HIV virus mutates so often that it often overcomes treatment with a single medication. HIV patients may need to change medication regimens because treatment is long term, and the HIV virus can become resistant to certain antivirals after treatment for an extended period. Combination pills containing two or more drugs are available. Examples of HIV antivirals include ritonavir, atazanavir, tenofovir, lamivudine, emtricitabine, abacavir, efavirenz, enfurvitide, raltegravir, and maraviroc.
Are a natural part of the immune system that the body releases in response to viral infection. They are given as injections in some viral diseases to help the body recognize the virus and increase the immune system response to fight the virus. Viral diseases that may be treated with interferons include hepatitis, West Nile Virus, and severe cases of genital warts. Examples of interferons given for viral illness include interferon alfa-2b, interferon alfa-n3, and peginterferon alfa-2a.
Are immune system proteins that bind to foreign invaders, such as viruses, and trigger the immune system to work to fight the infection. Antibodies are given by injection/IV infusion to help treat several viral diseases, including COVID-19, Hepatitis, Ebola, Respiratory Syncytial Virus (RSV), and Epstein-Barr Virus. Antibodies may also be given to help prevent infection in patients who have been exposed to dangerous viruses such as hepatitis and COVID-19. Antibodies are administered in the form of monoclonal antibodies, immune globulin infusion/injection, and convalescent plasma. Convalescent plasma involves infusion of the plasma component of blood of someone who has previously been infected by a virus to provide antibodies.
Common side effects that you may experience while taking antiviral medications include:
Drug Interactions are common with many antivirals. Some can be severe and require a change in medication therapy, so it is important that your prescriber and pharmacist know all medications you are taking.
Allergic Reactions -Signs and symptoms of allergic reactions include rash, hives, swelling, itching, shortness of breath, or a sensation of tightness in the throat or chest and may be accompanied by nausea and vomiting. Seek medical advice if you experience these symptoms while taking these medications. If shortness of breath or chest tightness/throat swelling is present, this is an emergency that needs immediate medical attention.
Organ Damage, especially to the liver or kidneys, is possible with several antiviral medications. Signs and symptoms of organ damage include decreased urination, abdominal pain, and yellowing of the skin or whites of the eyes. If you have a serious infection that requires long-term treatment, it is important to keep all medical appointments and have regular blood draws, which can often detect abnormal lab values that indicate organ damage before symptoms occur.
Blood count abnormalities such as low red or white blood cells or platelets are possible with several medications. If you have abnormal or unexplained bruising, easy bleeding, or a cut that takes an unusually long time to stop bleeding, seek medical attention. These blood abnormalities may also be detected with regular blood draws during long-term treatment.
Infusion-related reactions are common with different types of antibody infusions. These include nausea, vomiting, fever, chills, body aches, wheezing, and chest tightness. These can usually be managed by slowing down the infusion and/or giving medications to help control symptoms before infusion.
Many infectious diseases can be prevented with proper infection control measures. It is important to practice good hygiene, wash your hands frequently, use safe food preparation practices, and practice safe sex. You should also avoid close contact with anyone you know that is sick and consider wearing a mask in public during periods of high respiratory disease cases, including influenza and COVID-19. There are also vaccines available that can help prevent many viral diseases. Talk to your healthcare provider about vaccines that may be available to you.