What are antivirals?

Antivirals are medications designed to prevent or treat viral infections by inhibiting the development and spread of viruses. Unlike antibiotics, which target bacteria, antivirals are specific to viruses and are used to manage a variety of viral conditions.

They work by interfering with the virus’s ability to replicate within the body, thereby reducing symptoms, shortening the duration of illness, and preventing complications.

Antivirals are critical in the management of various viral infections, including influenza, herpes viruses, and more recently, the coronavirus responsible for COVID-19.

Their use is particularly significant in treating patients who are at high risk of developing severe disease, as they can prevent the progression to more serious illness and reduce the likelihood of hospitalization.

What are antivirals used to treat?

Antivirals are used to treat a variety of viral infections, each targeting specific types of viruses. Here’s a list of some common conditions that antiviral medications are used to manage:

• Influenza (Flu): Antivirals like oseltamivir and zanamivir are often prescribed to reduce the severity and duration of flu symptoms.
• Herpes viruses:
  • Genital herpes: Medications such as acyclovir, valacyclovir, and famciclovir help manage outbreaks.
  • Cold sores (oral herpes): Similar antivirals are used to speed up healing and reduce the frequency of flare-ups.
  • Shingles (herpes zoster): Antivirals can decrease pain and the likelihood of complications from shingles.
• Hepatitis B and C: Antivirals like tenofovir and ribavirin are crucial in managing chronic hepatitis, aiming to prevent liver damage.
• HIV/AIDS: A combination of antiviral drugs is used in antiretroviral therapy to control HIV infection.
• Respiratory syncytial virus (RSV): Medications such as ribavirin can be used to treat severe RSV infections, particularly in high-risk patients.
• COVID-19: Antivirals such as remdesivir and the combination of nirmatrelvir and ritonavir (Paxlovid) are used to treat COVID-19 in certain populations.

Types of antiviral medication

Antiviral medications are classified based on the type of viruses they target and their mechanism of action. Here are some of the main types:

• Nucleoside analogues: These mimic the building blocks of viral DNA or RNA, interrupting the viral replication process. Commonly used nucleoside analogues include acyclovir for herpes viruses and ribavirin for hepatitis C and RSV.
• Protease inhibitors: These interfere with the enzyme protease, which is crucial for the maturation of viral proteins. Protease inhibitors are key in treating HIV and hepatitis C. Examples include ritonavir and simeprevir.
• Neuraminidase inhibitors: Targeting the neuraminidase enzyme, these drugs prevent the release of new viral particles from infected cells, effectively stopping the spread of the virus within the body. Oseltamivir (Tamiflu) and zanamivir (Relenza) are commonly prescribed for influenza.
• Entry inhibitors: These prevent viruses from entering human cells, thus stopping the infection before it can start replicating. Maraviroc, used for HIV, is an example of an entry inhibitor.
• Integrase inhibitors: Specific to HIV, these drugs prevent the integration of viral DNA into the human DNA, a critical step for viral replication. Examples include raltegravir and dolutegravir.
• RNA polymerase inhibitors: These inhibit the RNA polymerase enzyme, essential for viral replication. Remdesivir, used for treating COVID-19, is an example of this class.

Each type of antiviral medication is designed for specific viruses and treatments, and their use depends on the individual patient’s condition and the specifics of the viral infection they are dealing with.

How does antiviral medication work?

Antiviral medications work by interfering with the viral replication process, which is essential for viruses to spread and cause illness. Here’s a general overview of how they achieve this:

• Inhibition of viral entry: Some antivirals prevent viruses from entering human cells. For example, entry inhibitors block receptors on the host cell’s surface or fuse with the viral envelope, preventing the virus from docking and penetrating the cell.
• Blocking viral replication: Once a virus enters a cell, it tries to use the cell’s machinery to replicate its genetic material. Nucleoside analogues, for instance, mimic the building blocks of viral DNA or RNA. When the virus incorporates these analogues into its genome, they act as chain terminators, stopping further replication.
• Inhibition of viral assembly and release: Other drugs target later stages of the viral life cycle, such as protein processing and virus assembly. Protease inhibitors, for instance, prevent viral protease enzymes from cutting long protein chains into the smaller functional units the virus needs to assemble new viral particles. Neuraminidase inhibitors prevent the release of newly formed viral particles by inhibiting the enzyme that cleaves sialic acid, a component of the host cell’s surface necessary for viral release.

Side effects of antivirals

Some common side effects associated with antiviral medications include:

• Gastrointestinal issues: Many antivirals can cause nausea, vomiting, diarrhea, and abdominal pain. These are among the most common side effects and are often manageable with dietary adjustments or additional medications to alleviate symptoms.
• Headache and dizziness: These are also common and can range from mild to severe. Some patients may experience these symptoms shortly after taking the medication.
• Fatigue and malaise: Feeling unusually tired or weak can occur, particularly in the initial stages of treatment as the body adjusts to the medication.
• Skin reactions: Rashes, itching, and other skin irritations can occur, especially with drugs that affect the immune system or skin directly.
• Neuropsychiatric effects: Some antivirals, particularly those used to treat influenza or HIV, can cause mood changes, confusion, or even hallucinations.
• Liver and kidney function: Certain antivirals can affect liver or kidney function, which may require regular monitoring through blood tests to ensure that the organs are functioning properly.
• Blood-related changes: Some medications may cause changes in blood cell counts, leading to conditions like anemia or thrombocytopenia (low platelet count).
• Allergic reactions: Although rare, severe allergic reactions like anaphylaxis can occur and require immediate medical attention.
• Specific drug-related side effects: For example, protease inhibitors used in HIV treatment can increase cholesterol and triglyceride levels, potentially leading to cardiovascular issues over time.

List of common antivirals

Here is a list of some commonly prescribed antiviral medications and the conditions they typically target:

• Acyclovir (Zovirax) – Used primarily to treat herpes simplex virus infections and varicella-zoster (shingles and chickenpox).
• Valacyclovir (Valtrex) – Effective against herpes simplex virus types 1 and 2, including genital herpes, and also used to treat shingles.
• Oseltamivir (Tamiflu) – Prescribed for the treatment and prevention of influenza A and B.
• Zanamivir (Relenza) – Another drug used to treat influenza A and B, administered via inhalation.
• Famciclovir (Famvir) – Used to treat herpes zoster (shingles), genital herpes, and herpes labialis (cold sores).
• Ribavirin – Used in combination with other medications to treat hepatitis C, and sometimes used for respiratory syncytial virus (RSV).
• Sofosbuvir (Sovaldi) – A cornerstone drug used in combination therapies for chronic hepatitis C.
• Lamivudine (Epivir) – Used to treat HIV and chronic hepatitis B.
• Tenofovir (Viread) – Commonly used for HIV infection and chronic hepatitis B.
• Raltegravir (Isentress) – An integrase inhibitor used to treat HIV.

How can DrHouse help?

DrHouse offers convenient telehealth services that are accessible 24/7, allowing patients to receive expert medical care whenever they need it. Through our user-friendly app, individuals can connect with healthcare professionals who specialise in a wide range of conditions.

Whether it’s a minor ailment or a chronic issue requiring ongoing management, our platform provides a seamless pathway to consult with medical experts from the comfort of your home. With the ability to receive prescriptions, guidance, and follow-up care, DrHouse ensures that patients have the support necessary for effective health management at any time.

Don’t let your health concerns go unaddressed. Sign up for DrHouse’s telehealth services today and gain access to a team of dedicated healthcare professionals ready to assist you.

Frequently asked questions (FAQs)

Can I get an online prescription for antivirals from DrHouse?

Yes, if our healthcare professionals determine that antiviral medication is necessary for your condition, they can provide a prescription through our telehealth platform. It’s essential to note that prescriptions are only provided when medically appropriate and in accordance with local laws and regulations.