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Antiviral for COVID-19: All You Need to Know

Written by Ada’s Medical Knowledge Team

Updated on


  • COVID-19 antivirals are meant to decrease the risk of hospitalization for those at risk of severe illness.
  • You can only get antiviral pills for COVID-19 with a prescription from your physician.
  • Several options are available: Paxlovid, Veklury, and Lagevrio.
  • Paxlovid and Lagevrio are antiviral pills, meaning they must be swallowed. Veklury is injected directly into the bloodstream through a vein. 
  • Treatment with COVID-19 antiviral medication should be started as soon as possible to be effective.

Antivirals for COVID-19 can help your immune system tackle the coronavirus and decrease your chances of falling seriously ill. They make it possible for patients with risk factors to have a better disease outcome, especially if treatment is initiated soon after testing positive for COVID-19. 

This article will guide you through COVID antiviral medication, the options available, how to get a prescription, and which side effects you might encounter.

What is COVID-19 antiviral medication? 

Antivirals for COVID-19 are an important treatment possibility for those at risk of falling severely ill due to an infection with the coronavirus. Usually, our immune system detects, targets, and eliminates virus particles in the body. However, some people's immune system isn't strong enough to overcome the infection.

For those at risk, COVID-19 antiviral medication is an effective solution. These antiviral drugs will target specific parts of the virus to prevent it from multiplying in the body. This reduces the amount of the virus present in the body while your immune system is fighting the virus. By doing so, antiviral medicine can help prevent severe illness, hospitalization, and even death

Antiviral medication for COVID-19 can improve the condition's outcome so that possible hospitalization may be avoided. It's, however, essential to note that treatment with these oral antivirals should be started as soon as possible after receiving a positive COVID-19 test result.

How to get antiviral medication for COVID-19?

Antivirals for COVID-19 must be prescribed by a healthcare professional who will carefully consider your specific medical situation. To get COVID-19 antiviral medication, you should:1

  • Be 12 years or older
  • Be at risk of developing severe symptoms or being hospitalized because of your illness
  • Have had mild to moderate symptoms for 5 days or less
  • Not be hospitalized 

You're eligible for COVID-19 antiviral pills if you meet all these criteria. Your healthcare provider will give you a prescription to get this medication.

Who should get antivirals for COVID-19?

Antiviral drugs for COVID-19 are recommended for those with a weakened immune system and, therefore, run a higher chance of falling seriously ill because of an infection with the coronavirus. COVID-19 antiviral treatment can stop the virus from replicating properly so that the chances of hospital admission decrease drastically. They should be taken while you are still experiencing mild to moderate symptoms so they do not worsen. You may require hospitalization if you're experiencing severe symptoms.

In case you are hospitalized, antiviral medication such as Remdesivir is also commonly administered to those who present signs of severe illness.2

People at risk for severe illness due to COVID-19 usually have underlying health conditions such as:2

Which antivirals for COVID-19 are currently available? 

The FDA has approved remdesivir, also known as Veklury, as an antiviral treatment for COVID-19. Nirmatrelvir with ritonavir (Paxlovid) and molnupiravir (Lagevrio) received FDA's emergency use authorizations as an antiviral for COVID-19. Your physician will prescribe your antiviral medication for COVID-19 based on your situation and medical history.3


Paxlovid is an oral antiviral medication useful for adults and children older than 12 years. You should start taking Paxlovid as soon as possible, from the moment that you’ve tested positive for an infection with the coronavirus. You must begin the treatment within the first 5 days for the COVID-19 antiviral to be effective. 

Paxlovid consists of 2 different tablets: nirmatrelvir and ritonavir. Your healthcare provider will advise you on how many pills to take. Usually, this will be 1 dose of Paxlovid (consisting of 2 tablets of nirmatrelvir and 1 tablet of ritonavir), which you’ll need to take twice a day for 5 days. 

It's essential to take these antiviral pills for the entire time of their prescription, even if you're feeling better. It’s also vital to always mention any other medications you might be taking, as they might interfere with Paxlovid, leading to serious drug-drug interactions.

Even though Paxlovid is effective, not everyone at high risk for severe illness from COVID-19 is being prescribed this drug. The reason behind this may be fear of drug-drug interactions, as many of those at high risk also use other types of medications for underlying illnesses. Another possible reason why Paxlovid is not being prescribed as much may be the fear of a COVID-19 rebound. This is a situation in which COVID-19 symptoms suddenly return 2 to 8 days after having completed a 5-day course of Paxlovid. Studies suggest that for Paxlovid and Molnupiravir, a COVID-19 rebound is possible, especially in patients with underlying medical conditions.4 5


Lagevrio (also known as molnupiravir) is another antiviral COVID-19 pill that is helpful for adults aged 18 and older and can be taken at home. Like Paxlovid, it comes as capsules that should be swallowed. Treatment with Lagevrio must also begin within 5 days of the symptom onset to be effective. Your physician will advise you on which dosage of Lagevrio you should take. Usually, this will be 4 capsules every 12 hours for 5 days. Even if you feel better, you should complete the entire treatment and follow your doctor's advice. Currently, Lagevrio is not FDA-approved, and its use is only authorized in specific circumstances as an emergency solution for COVID-19.6


Veklury (remdesivir) is also an antiviral treatment option for COVID-19, which can be used for adults and children. Treatment should also begin as soon as possible, within 7 days of experiencing symptoms. Unlike Paxlovid and Lagevrio, Veklury isn't an oral antiviral but an intravenous antiviral. This means that a healthcare provider administers it through a vein for 3 consecutive days.7 8

Adequate knowledge by healthcare providers and improved public awareness of the benefits of these antivirals against COVID-19 can increase their usage and further improve the outcome of COVID.

What are the possible side effects of COVID-19 antiviral medication? 

Antivirals for COVID-19 may cause side effects. Usually, they're mild and do not last long, but it's crucial to follow up and contact your healthcare provider if you're worried about your health.

When getting the prescription for COVID antiviral pills, you must inform your healthcare provider about your medical history and any other medications you're currently on. That way, your doctor can assess the possible risks when prescribing a COVID-19 antiviral drug. 

Common possible side-effects of Paxlovid are:8

  • Diarrhea
  • Nausea or vomiting
  • Alterations to your sense of taste

There are currently no serious side effects known for Paxlovid. In rare cases, however, it's possible to have an allergic reaction to this drug, which can include hives, throat tightness, mouth swelling, rapid heartbeat, skin rash, or trouble breathing. If you notice these symptoms, then you should seek immediate medical help.

Other less common side effects may include: 

  • Liver problems, which can present themselves in the form of jaundice (yellowing of the skin and whites of the eyes), loss of appetite, dark-colored urine, pale stools, itchy skin, and pain in the stomach area.
  • High blood pressure
  • Muscle aches
  • Abdominal pain

For Lagevrio, these are the most common side-effects:9

  • Diarrhea
  • Nausea or vomiting
  • Dizziness
  • Headaches

There are no known serious side effects with Lagevrio. In rare cases, it's possible to have a severe allergic reaction with hives, throat tightness, mouth swelling, rapid heartbeat, skin rash, or trouble breathing. If you notice any of these symptoms, you should seek medical help immediately.

The use of Lagevrio is not recommended during pregnancy or for those who are breastfeeding, as it may be harmful to your baby.10

Veklury can also cause side effects, including: 11

  • Headache
  • Nausea
  • Vomiting

In some cases, Veklury can cause an allergic reaction with hives, throat tightness, mouth swelling, rapid heartbeat, skin rash, or trouble breathing. If you notice any of these symptoms, then you should seek immediate medical assistance.

Not everyone experiences side effects, but knowing that they might occur is essential. If you experience any symptoms that worry you after starting your COVID-19 antiviral treatment, you should contact your healthcare provider immediately. Especially do so if:

  • You’re feeling confused
  • You have chest pain
  • You fainted
  • You have difficulty breathing 
  • You're experiencing a severe allergic reaction with red, swollen, blistered skin, mouth swelling, and chest or throat tightness

Wrapping up

Antivirals for COVID-19 are available to those who are eligible for a prescription. To get antiviral medication, your physician must assess your health status and the risk you run of falling severely ill due to the coronavirus. These antiviral medications for COVID-19 will help your immune system by preventing the virus from multiplying in the body. This way, severe consequences due to the infection can be avoided. 


Q: What is the most effective antiviral for COVID-19?
A: Paxlovid, Veklury, and Lagevrio are all effective antivirals for COVID-19. Your physician will analyze your medical situation to decide which antivirals best fit you.

Q: When to take antiviral for COVID-19
A: If you are at risk of developing severe illness,, you should start the treatment with antivirals for COVID-19 as soon as you test positive for an infection with the coronavirus, even if your symptoms are mild. 

Q: How does Paxlovid treat COVID-19? 
A: Paxlovid stops the virus from multiplying in the body, which helps your immune system overcome the infection. 

Q: What is Paxlovid? 
A: Paxlovid is an antiviral pill to treat COVID-19. It consists of 2 separate pills which you have to take together. If you’re a at risk for severe illness, taking Paxlovid can help you prevent severe symptoms and hospitalization. 

Q: Who should not take Paxlovid? 
A: Paxlovid won’t be prescribed to those who aren’t at risk of falling severely ill with COVID-19. It’s recommended that these people use home remedies while their immune system handles the infection.