I've heard several drugs mentioned as possible treatments for COVID-19. What are they and how do they work?
Answer From Daniel C. DeSimone, M.D.
There is only one product approved by the U.S. Food and Drug Administration (FDA) to treat coronavirus disease 2019 (COVID-19). But many medications are being tested.
The FDA has approved an antiviral drug called remdesivir (Veklury) to treat COVID-19 in adults and children who are age 12 and older. Remdesivir may be prescribed for people who are hospitalized with COVID-19 and need supplemental oxygen or have a higher risk of serious illness. It's given through a needle in the skin (intravenously).
The FDA has authorized for emergency use a drug called Paxlovid. This drug combines two types of medications in one package. The first drug is nirmatrelvir. It blocks the activity of a specific enzyme needed for the virus that causes COVID-19 to replicate. The second drug is an antiviral drug called ritonavir. It helps slow the breakdown of nirmatrelvir. Paxlovid is authorized to treat mild to moderate COVID-19 in people age 12 and older who are at higher risk of serious illness. The medications are taken by mouth as pills.
The FDA has authorized for emergency use another drug called molnupiravir to treat mild to moderate COVID-19 in adults who are at higher risk of serious illness and not able to take other treatments. The medication is taken by mouth as a pill.
The FDA has authorized for emergency use the rheumatoid arthritis drug baricitinib (Olumiant) to treat COVID-19 in some cases. Baricitinib is a pill that seems to work against COVID-19 by reducing inflammation and having antiviral activity. Baricitinib may be used in people who are hospitalized with COVID-19 who are on mechanical ventilators or need supplemental oxygen.
Researchers are studying other potential treatments for COVID-19, including:
- Antiviral drugs. Researchers are testing the antiviral drugs favipiravir and merimepodib. Studies have found that the combination of lopinavir and ritonavir isn't effective.
- Anti-inflammatory therapy. Researchers study many anti-inflammatory drugs to treat or prevent dysfunction of several organs and lung injury from infection-associated inflammation.
Dexamethasone. The corticosteroid dexamethasone is one type of anti-inflammatory drug that researchers are studying to treat or prevent organ dysfunction and lung injury from inflammation. Studies have found that this drug reduces the risk of death by about 30% for people on ventilators and by about 20% for people who need supplemental oxygen.
The U.S. National Institutes of Health has recommended dexamethasone for people hospitalized with COVID-19 who are on mechanical ventilators or need supplemental oxygen. If dexamethasone isn't available, other corticosteroids, such as prednisone, methylprednisolone or hydrocortisone, may be used. Dexamethasone and other corticosteroids may be harmful if given for less severe COVID-19 infection.
In some cases, the drugs remdesivir, tocilizumab or baricitinib may be given with dexamethasone in hospitalized people who are on mechanical ventilators or need supplemental oxygen.
Immune-based therapy. Researchers study immune-based therapies, including convalescent plasma, mesenchymal stem cells and monoclonal antibodies. Monoclonal antibodies are proteins created in a lab that can help the immune system fight off viruses.
The FDA has authorized for emergency use the monoclonal antibody combination of tixagevimab and cilgavimab (Evusheld) to prevent COVID-19 in some people with weakened immune systems or a history of severe reactions to a COVID-19 vaccine. But Evusheld may provide less or no protection against certain omicron strains of the virus.
Other monoclonal antibodies aren't effective against treating COVID-19 caused by the omicron variant either. These drugs were previously used to treat mild to moderate COVID-19 in people who had a higher risk of developing serious illness due to COVID-19.
Researchers also study the use of a type of immune-based therapy called convalescent plasma. The FDA has authorized for emergency use convalescent plasma therapy to treat COVID-19. Convalescent plasma is blood donated by people who've recovered from COVID-19. Convalescent plasma with high antibodies may be used to treat some hospitalized people with COVID-19 who are either early in their illness or have weakened immune systems.
- Drugs being studied that have uncertain effectiveness. Researchers study amlodipine and losartan. But it's not yet known how effective these drugs may be in treating or preventing COVID-19. Famotidine isn't thought to be beneficial in treating COVID-19.
- Ivermectin. The drug ivermectin, used to treat or prevent parasites in animals and in humans, isn't a drug used to treat viruses. The FDA hasn't approved use of this drug to treat or prevent COVID-19. Taking large doses of this drug can cause serious harm. Don't use medications intended for animals on yourself to treat or prevent COVID-19.
- Hydroxychloroquine and chloroquine. These malaria drugs were authorized for emergency use by the FDA during the COVID-19 pandemic. However, the FDA withdrew that authorization when data analysis showed that the drugs are not effective for treating COVID-19. They can also cause serious heart problems.
Drugs to prevent COVID-19. Researchers are studying drugs to prevent COVID-19 before and after exposure to the virus.
It's not known if any of these will prove to be effective against COVID-19. It's critical to complete medical studies to determine whether any of these medications are effective against COVID-19.
Don't try these medications without a prescription and your health care provider's approval, even if you've heard that they may have promise. These drugs can have serious side effects. They're reserved for people who are seriously ill and under a health care provider's care.
Daniel C. DeSimone, M.D.
Jan. 20, 2023
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Original article: https://www.mayoclinic.org/diseases-conditions/coronavirus/expert-answers/coronavirus-drugs/faq-20485627