COVID Pharmacotherapy FAQs: Addressing Patient Questions

(Updated January 20, 2021)

There is a lot of misinformation regarding COVID-19 on the internet. The chart below provides information to help answer questions and correct misconceptions about pharmacotherapy as it relates to COVID-19. Dietary supplements that patients often want to try for COVID-19 are also addressed. Another source of information to help dispel false beliefs related to COVID-19 is the World Health Organization’s “Coronavirus Disease (COVID-19) Advice for the Public: Mythbusters,” at See our chart, Treatments of Interest for COVID-19, for information and resources on drugs, convalescent plasma, and dietary supplements being investigated for COVID-19.

Clinical question

Pertinent information or resource

Do ACE inhibitors or ARBs make COVID-19 worse?

The SARS-CoV-2 virus uses ACE2 to enter cells.1 ACE inhibitors and ARBs may upregulate ACE2.1 In theory, these drugs could thereby facilitate virus entry into cells.1 But on the other hand, blocking angiotensin could reduce lung injury.1

No evidence suggests that patients taking an ACEI or ARB are more susceptible to COVID-19 infection, or that these medications worsen outcomes.2-5 One cohort study even suggests reduced mortality in COVID-19 patients taking them for other indications.3 Furthermore, we know that these drugs benefit patients with diabetic nephropathy and cardiovascular disease, populations at risk of severe COVID-19 disease.1,6

Patients should continue these medications. See statements from:

Can NSAIDs be used in COVID-19-infected patients?

Anecdotal reports regarding worse COVID-19 outcomes in patients taking NSAIDs have spread in the media and on social media, including via a tweet from a French health official.2,7 In 2019, a French report suggested that NSAIDs could worsen infections, mainly Strep, perhaps by masking symptoms.8,9 However, there is currently no reliable clinical data supporting worse outcomes in patients taking NSAIDs or aspirin.2,10 Preclinical data is mixed on the potential effects of NSAIDs on COVID-19 (increased expression of ACE2, which the virus uses to enter cells, vs potential antiviral activity of NSAIDs).2

Patients taking low-dose aspirin should not stop taking it because of COVID-19 concerns.2 There is interest in studying aspirin for prevention of thromboembolic and other COVID-19 complications.32 NIH guidance advises that aspirin should not be started in nonhospitalized patients solely to prevent COVID-19-related thrombosis outside of a clinical trial.28

Neither the FDA nor Health Canada is advising changes to NSAID use due to COVID-19.10,11

Are any supplements effective for prevention or treatment of COVID-19?

Patients are using supplements as immune boosters (e.g., echinacea, colloidal silver, green tea, selenium, vitamin C, vitamin D) or for their purported antiviral activity (e.g., elderberry, garlic, oleander, quercetin, zinc). However, there is no scientific evidence that any alternative remedies can prevent or treat COVID-19, and some products may not be safe.12

The following are unsafe plants or supplements that patients should be advised to avoid.

  • Oleander has led to fatal poisonings. All parts of the plant contain cardiac glycosides. Other components have central nervous system depressant effects or strychnine-like actions.13
  • Colloidal silver accumulates in the body and can cause permanent skin discoloration, neurologic toxicity (e.g., seizures), and liver or kidney damage.16
  • Intranasal zinc can cause permanent loss of smell.20

Ashwagandha (an “adaptogen”) should be avoided in pregnancy, as it may cause miscarriage. It is possibly safe for nonpregnant adults at doses up to 1,000 mg/day for up to 12 weeks. It may cause GI side effects and dermatitis, and rarely, hepatotoxicity. It may stimulate thyroid hormone production or secretion, suppressing TSH and increasing T3 or T4.22

Advise limiting green tea (beverage) to eight cups daily, due to caffeine content.23 Green tea oral extract is possibly safe when used as directed.23 However, there are reports of hepatotoxicity with green tea extracts.23 Advise taking this form with food to limit this risk.23 It should be avoided in patients with liver impairment.23

Elderberry extract is possibly safe. People allergic to grass pollen might experience rhinitis or dyspnea. Raw or unripe fruit, or plant parts other than the fruit, should not be consumed; they contain cyanogenic glycosides that can cause GI side effects.26 Proper cooking eliminates the toxin, but teas and hot drinks have also caused GI effects.26 Neurologic side effects have also been reported.26

Quercetin is generally well-tolerated, but headache and paresthesia have been reported.27

Products of interest that are likely safe when taken orally and as directed include echinacea, garlic (note antiplatelet effect), and American ginseng.17-19 Panax ginseng (red ginseng) is likely safe when used for up to six months. Hormonal effects are of concern with longer use.24 Resveratrol is likely safe when consumed in foods, but high doses of supplements may cause GI side effects.25

Advise patients self-medicating with selenium, vitamin E, or other vitamins or minerals to stick with doses approximating recommended intakes to minimize risks.21

Several studies are looking at multivitamin/mineral combos as adjuncts for treatment or prevention. See for more information. For information on zinc, vitamin C, and vitamin D, see our chart, Treatments of Interest for COVID-19.

See our Natural Medicines database ( for information on efficacy and safety (including drug interactions) of specific alternative medicines.

Are any antimicrobials effective for COVID-19?

Antibiotics are appropriate for bacterial pneumonia or sepsis.28

NIH guidance recommends neither for nor against the use of ivermectin for the treatment of COVID-19 due to insufficient evidence.28 The FDA has similar advice, and warns against human use of ivermectin intended for animals.31 For more information on ivermectin for COVID-19, see our chart, Treatments of Interest for COVID-19.

The FDA revoked its Emergency Use Authorizations for chloroquine and hydroxychloroquine because data showed that they were unlikely to be effective, and known and potential benefits are outweighed by potential side effects.29 NIH guidance recommends against their use for the treatment of COVID-19 in hospitalized patients, and in nonhospitalized patients except in a clinical trial (with or without azithromycin).28

Are corticosteroids effective for COVID-19?

Dexamethasone (or equivalent systemic corticosteroid) provides a mortality benefit in hospitalized patients requiring oxygen, especially in those who require mechanical ventilation.28 Its mechanism is likely anti-inflammatory rather than antiviral; inflammation is more common in advanced disease, while viral replication is at maximum in early disease.30 Dexamethasone has not provided a mortality benefit for patients not requiring oxygen, and may be harmful.30

For more information on dexamethasone and other corticosteroids for COVID-19, see our chart, Treatments of Interest for COVID-19.

Are heartburn drugs effective for treating or preventing COVID-19?

For information on famotidine, see our chart, Treatments of Interest for COVID-19.

  • Proton pump inhibitor (PPI) use was associated with a higher risk of COVID-19 based on results of an online survey of ~53,000 English-speaking Americans, after controlling for confounders. Risk was higher for patients taking a PPI twice daily vs once daily. H2 blockers did not appear to increase risk. Any increased absolute risk of COVID-19 in PPI users is probably small. If patients ask about PPI use, consider this an opportunity to reevaluate treatment and reinforce COVID-19 preventive measures.14

Does nicotine protect against COVID-19?

In China, there was an unexpectedly low prevalence of smoking among patients hospitalized with COVID-19. Low smoking prevalence among hospitalized COVID-19 patients has also been seen in the U.S.15

Nicotine, through its cholinergic agonist activity, blocks production of inflammatory cytokines such as IL-6.15

There is interest in using nicotine, either as currently available products, or perhaps via nebulization, as an adjunct for COVID-19 treatment.15

Continue to use nicotine replacement products for nicotine users who are hospitalized for COVID-19, and for anyone who desires to quit smoking.15

Abbreviations: GI = gastrointestinal; TSH = thyroid stimulating hormone; T3 = triiodothyronine; T4 = thyroxine

Prepared by the Editors of Therapeutic Research Center (361003); Last modified January 20, 2021.


  1. Kuster GM, Pfister O, Burkard T, et al. SARS-CoV2: should inhibitors of the renin-angiotensin system be withdrawn in patients with COVID-19? Eur Heart J 2020;41:1801-3.
  2. Canadian Cardiovascular Society. Guidance from the CCS COVID-19 Rapid Response team. March 20, 2020. (Accessed September 8, 2020).
  3. Zhang P, Zhu L, Cai J, et al. Association of inpatient use of angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers with mortality among patients with hypertension hospitalized with COVID-19. Circ Res 2020;126:1671-81.
  4. Li J, Wang X, Chen J, et al. Association of renin-angiotensin system inhibitors with severity or risk of death in patients with hypertension hospitalized for coronavirus disease 2019 (COVID-19) infection in Wuhan, China. JAMA Cardiol 2020;5:825-30.
  5. Reynolds HR, Adhikari S, Pulgarin C, et al. Renin-angiotensin-aldosterone system inhibitors and risk of COVID-19. N Engl J Med 2020;382:2441-8.
  6. Yang X, Yu Y, Xu J, et al. Clinical course and outcomes of critically ill patients with SARS-CoV-2 pneumonia in Wuhan, China: a single-centered, retrospective, observational study. Lancet Respir Med 2020;8:475-81.
  7. Melville NA, Nainggolan L. Are warnings against NSAIDs in COVID-19 warranted? March 17, 2020. (Accessed September 9, 2020).
  8. European Medicines Agency. EMA gives advice on the use of non-steroidal anti-inflammatories for COVID 19. March 18, 2020. (Accessed September 9, 2020).
  9. Agence Nationale de Securite du Medicament et des Produits de Sante. Anti-inflammatoires non steroidiens (AINS) et complications infectieuses graves-point d’information. April 18, 2019. (Accessed September 8, 2020).
  10. FDA. FDA advises patients on use of non-steroidal anti-inflammatory drugs (NSAIDs) for COVID-19. March 19, 2020. (Accessed September 9, 2020).
  11. Health Canada. No scientific evidence that ibuprofen worsens COVID-19 symptoms. March 20, 2020. (Access September 9, 2020).
  12. NIH. National Center for Complementary and Integrative Health. In the news: coronavirus and “alternative” treatments. (Accessed September 9, 2020).
  13. TRC Healthcare. Oleander. [Natural Medicines website]. August 27, 2020. Available at:,-herbs-supplements/professional.aspx?productid=789. (Accessed September 9, 2020).
  14. American College of Gastroenterology. Information sheet and FAQs about proton pump inhibitors (PPIs) and risk of COVID-19. July 7, 2020. (Accessed September 9, 2020).
  15. Farsalinos K, Barbouni A, Niaura R. Systematic review of the prevalence of current smoking among hospitalized COVID-19 patients in China: could nicotine be a therapeutic option? Intern Emerg Med 2020;15:845-52.
  16. TRC Healthcare. Colloidal silver. [Natural Medicines website]. May 21, 2020. Available at:,-herbs-supplements/professional.aspx?productid=779. (Accessed September 9, 2020).
  17. TRC Healthcare. Echinacea. [Natural Medicines website]. May 6, 2020. Available at:,-herbs-supplements/professional.aspx?productid=981. (Accessed September 9, 2020).
  18. TRC Healthcare. Garlic. [Natural Medicines website]. July 28, 2020. Available at:,-herbs-supplements/professional.aspx?productid=300. (Accessed September 9, 2020).
  19. TRC Healthcare. American ginseng. [Natural Medicines website]. May 21, 2020. Available at:,-herbs-supplements/professional.aspx?productid=967. (Accessed September 9, 2020).
  20. TRC Healthcare. Zinc. [Natural Medicines website]. August 19, 2020. Available at:,-herbs-supplements/professional.aspx?productid=294. (Accessed September 12, 2020).
  21. NIH. Office of Dietary Supplements. October 17, 2019. (Accessed September 12, 2020).
  22. TRC Healthcare. Ashwagandha. [Natural Medicines website]. August 28, 2020. Available at:,-herbs-supplements/professional.aspx?productid=953. (Accessed September 9, 2020).
  23. TRC Healthcare. Green tea. [Natural Medicines website]. August 5, 2020. Available at:,-herbs-supplements/professional.aspx?productid=960. (Accessed September 9, 2020).
  24. TRC Healthcare. Panax ginseng. [Natural Medicines website]. August 5, 2020. Available at:,-herbs-supplements/professional.aspx?productid=1000. (Accessed September 9, 2020).
  25. TRC Healthcare. Resveratrol. [Natural Medicines website]. April 29, 2020. Available at:,-herbs-supplements/professional.aspx?productid=307. (Accessed September 9, 2020).
  26. TRC Healthcare. Elderberry. [Natural Medicines website]. May 13, 2020. Available at:,-herbs-supplements/professional.aspx?productid=434. (Accessed September 9, 2020).
  27. TRC Healthcare. Quercetin. [Natural Medicines website]. May 14, 2020. Available at:,-herbs-supplements/professional.aspx?productid=294. (Accessed September 9, 2020).
  28. NIH. Coronavirus disease 2019 (COVID-19). Treatment guidelines. Last updated January 14, 2021. (Accessed January 17, 2021).
  29. FDA. Frequently asked questions on the revocation of the Emergency Use Authorization for hydroxychloroquine sulfate and chloroquine phosphate. June 19, 2020. (Accessed January 9, 2021).
  30. RECOVERY Collaborative Group; Horby P, Lim WS, et al. Dexamethasone in hospitalized patients with COVID-19-preliminary report. N Engl J Med 2020 Jul 17. doi:10.1056/NEJMoa2021436.
  31. FDA. FAQ: COVID-19 and ivermectin intended for animals. December 16, 2020. (Accessed January 9, 2021).
  32. Bianconi V, Violi F, Fallarino F, et al. Is acetylsalicylic acid a safe and potentially useful choice for adult patients with COVID-19? Drugs 2020;80:1383-96.

Cite this document as follows: Clinical Resource, COVID-19 Pharmacotherapy FAQs: Addressing Patient Questions. Pharmacist’s Letter/Prescriber’s Letter. October 2020.

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