Managing Drug Interactions When Treating Patients for COVID-19

Physicians may earn a maximum of 1.5 AMA PRA Category 1 Credits™



  • Vidya Sundareshan MD MPH, FAMWA, Professor and Chief of Infectious Diseases at Southern Illinois University School of Medicine  and Medical Advisor, Sangamon County Department of Public Health
  • Vidhya Prakash, MD, Professor of Infectious Diseases, and Chief Medical Officer/Associate Dean of Clinical Affairs and Population Health at Southern Illinois University School of Medicine.

Framing the Issue of COVID Care

More than 131 million people — 66 percent of all adults in the United States — take prescription medications, according to a report by the Georgetown University Health Policy Institute. In fact, an estimated 75% of adults 50-64 years take up to 13 drugs daily, and the number of adults who require multiple medications rises to 87% among adults 65-79 years of age who are at an elevated risk for hospitalization and death following infection with COVID-19.

Adverse effects in patients who take multiple medications occur with greater frequency as individuals rise in age due to adverse drug effects, inappropriate treatment, nonadherence, and drug interactions. Older people are more than twice as susceptible to the side effects of drugs as younger individuals and almost 90% of seniors take multiple medications to manage chronic diseases.

Since the onset of the COVID-19 pandemic, the treatment armamentarium has continued to expand to improve patient outcomes. Antivirals used in the outpatient setting reduce mortality and hospitalization rates, especially in high-risk patients. Although the duration of antiviral therapy for COVID-19 is short, an important consideration for clinicians is to be aware of and adequately versed in known drug-drug interactions that can result in serious harm or reduced efficacy in COVID management or pose a known medical concern for medicines prescribed for ongoing management of chronic diseases.

Addressing Management of Patients with COVID and Pre-Existing Conditions

In order to assure that patients are able to respond optimally to treatments aimed to lessen symptoms and improve outcomes for individuals infected with the coronavirus, and at the same time to avoid adverse effects related to drugs taken daily by patients to manage chronic diseases, clinicians must be made aware of common drug-drug interactions and know about the clinical adjustments necessary to advise their patients.

Clinicians should be aware of key resources to manage and mitigate drug interactions while on oral antivirals, including those published by the National Institutes of Health and the Infectious Diseases Society of America. An important step while assessing eligibility for antivirals is to check the drug-drug interactions. In case of contraindications, other choices for the treatment of COVID-19 should be considered. With systematic review and education about the significant interactions, there will be enhanced comfort for clinicians in prescribing these effective antivirals in a safe manner for patients who will benefit from their use.

Learning Objectives:

After this session, participants will be able to:

  1. Describe risk factors for clinically relevant drug-drug interactions while on oral antivirals to treat COVID-19.
  2. List the major types of drug-drug interactions between oral antivirals, ritonavir-boosted nirmatrelvir (Paxlovid) and molnupiravir, and select classes of medications.
  3. Outline specific strategies to mitigate risks of drug-drug interactions when prescribing oral antivirals to treat COVID-19.
  4. Outline the various resources available for drug-drug interactions for antivirals used in the ambulatory setting for COVID-19

Continuing Education Information

Accreditation Statement

In support of improving patient care, this activity has been planned and implemented by Indiana University School of Medicine and AMWA. Indiana University School of Medicine is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.


Indiana University School of Medicine designates this enduring material activity for a maximum of 1.5 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Disclosure Summary

Indiana University School of Medicine (IUSM) policy ensures that those who have influenced the content of a CE activity (e.g. planners, faculty, authors, reviewers and others) disclose all financial relationships with any ineligible companies so that IUSM may identify and mitigate any conflicts of interest prior to the activity. All educational programs sponsored by Indiana University School of Medicine must demonstrate balance, independence, objectivity, and scientific rigor.

There are no relevant financial relationship(s) with ineligible companies for anyone who was in control of the content of this activity.

An ineligible company is any entity whose primary business is producing, marketing, selling, re-selling, or distributing healthcare products used by or on patients.

This activity is supported by an educational grant from Pfizer



  1. Prescription Drugs. Available: Accessed January 3, 2023.
  2. Overview of drug therapy in older adults. Available: Accessed January 3, 2023.
  3. Antiviral and Antibody Products Summary Recommendations | COVID-19 Treatment Guidelines. National Institutes Health. ( Available: Accessed January 3, 2022.
  4. Wen W, Chen C, Tang J, et al. Efficacy and safety of three new oral antiviral treatment (molnupiravir, fluvoxamine and Paxlovid) for COVID-19: a meta-analysis. Ann Med. 2022;54(1):516-523. doi: 10.1080/07853890.2022.2034936.
  5. Marzolini C, Kuritzkes DR, Marra F, Boyle A, Gibbons S, Flexner C, Pozniak A, Boffito M, Waters L, Burger D, Back DJ, Khoo S. Recommendations for the Management of Drug-Drug Interactions Between the COVID-19 Antiviral Nirmatrelvir/Ritonavir (Paxlovid) and Comedications. Clin Pharmacol Ther. 2022;112(6):1191-1200. doi: 10.1002/cpt.2646.
  6. Management of Drug Interactions With Nirmatrelvir/Ritonavir (Paxlovid®): Resource for Clinicians. Available: Accessed December 27, 2022.