By: Imaan Sekhery, PharmD Candidate c/o 2025

​              On July 6, 2022, the Food and Drug Administration (FDA) revised the precedent Emergency Use Authorization (EUA) for Pfizer’s Paxlovid, granting licensed pharmacists the right to prescribe Paxlovid to suitable patients. This revision will significantly increase access to Paxlovid, assisting in patient recovery from Coronavirus Disease 2019 (COVID-19). Limitations have been set to ensure pharmacists prescribe the antiviral pills to eligible patients. Sufficient information should be available to assess renal and hepatic function and to check for any potential drug interactions.¹ This FDA approval is linked to the Public Readiness and Emergency Preparedness (PREP) Act passed during the COVID-19 pandemic, which provided liability protection to licensed pharmacists, pharmacy interns, and pharmacy technicians.² Paxlovid is approved to be used within five days after symptom onset.¹ The change to allow pharmacists to prescribe Paxlovid helps provide early treatment for COVID-19 patients in need. 

Paxlovid consists of nirmatrelvir, a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease inhibitor, along with ritonavir, an HIV-1 protease inhibitor and CYP3A inhibitor. Ritonavir is not effective against SARS-CoV-2 on its own, however, by inhibiting the CYP3A-mediated metabolism of nirmatrelvir, ritonavir increases plasma concentrations of nirmatrelvir, resulting in further inhibition of SARS-CoV-2 replication.³ The drug has been authorized to treat patients ages 12 and older, who weigh at least 88 pounds. Patients must have tested positive for COVID-19 through either a rapid antigen home test or a polymerase chain reaction (PCR) test.¹ Paxlovid is to be taken as three tablets twice daily for five days straight. Each package contains a total of 30 tablets.⁴ 

Although pharmacists have been able to prescribe Paxlovid for some time now, there hasn’t been as high of a demand for the drug as planned. Small pharmacy owner Adeolu Odewale weighed in on the situation from Washington, D.C., expressing his confusion as to why his pharmacy had only dispensed the medication to seven people after having the antiviral pills in stock for well over a month. Dr. Odewale stated, “I didn’t expect that I was still going to be sitting on that many of them,” unsure of why more patients weren’t utilizing this option.⁵ Pharmacists insist that the possibility of patients being unaware of how to be eligible and receive Paxlovid to treat themselves may be a factor in why they don’t pursue the medication, but others are beginning to question whether pharmacists are truly comfortable with prescribing Paxlovid.  

Pfizer’s prescribing information states that Paxlovid can be recommended to patients with mild to moderate hepatic impairment, as well as to patients with an eGFR greater than 30 and less than 60 mL/min. Paxlovid is not recommended in patients with severe hepatic or renal impairment.⁶ Several local California pharmacists from CVS, Rite Aid, and Walgreens have mentioned that one of the prevailing reasons they won’t prescribe Paxlovid themselves is because of the guidelines requiring pharmacists to review liver and kidney function tests.⁷ For patients to receive pharmacist-prescribed Paxlovid, pharmacists must review the patient’s medication list   (both prescription and over the counter), health records from the last twelve months, and most recent laboratory blood work.¹ Earlier this year, the Biden Administration launched the “Test to Treat” federal program, allowing people to get tested for COVID-19 and receive Paxlovid on the spot,² however, this has yet to speed up accessibility of the drug. 

 Another difficulty with prescribing Paxlovid is the possibility of rebound COVID-19. According to case reports from the first half of 2022, patients treated with Paxlovid experienced rebound COVID-19 infections and symptoms just 2 to 8 days after completing their 30 tablet regimen.⁸ A cohort study involving 92 million patient electronic health records from a multicenter and nationwide database in the United States was conducted to determine the prevalence of rebound effects from Paxlovid and Molnupiravir.⁸ The study population consisted of 13,644 patients, all of whom were at least 18 years old, contracted COVID-19, and were treated with either Paxlovid (n =11,270) or Molnupiravir (n =2,374) within five days of symptom onset.  

The 7-day risk for COVID-19 rebounds in patients who took Paxlovid vs Molnupiravir were 4.54% and 5.95% for COVID-19 infection (Hazard Ratio [HR] 0.81; 95% Confidence Interval [CI] 0.63 to 1.05), 2.61% and 3.77% for COVID-19 symptoms (HR 0.74; 95% CI 0.53 to 1.03), and 0.67% and 0.90% for hospitalizations (HR 0.78; 95% CI 0.40 to 1.51), respectively.⁸ The 30-day risk for COVID-19 rebounds in patients who took Paxlovid vs Molnupiravir were 7.14% and 8.49% for COVID-19 infection (HR 0.90; 95% CI 0.73 to 1.11), 7.55% and 8.00% for COVID-19 symptoms (HR 1.03; 95% CI 0.83 to 1.27), and 1.21% and 1.39% for hospitalizations (HR 0.92; 95% CI 0.55 to 1.55), respectively.⁸ The above data shows that after propensity-score matching, both the 7-day and 30-day risks for COVID-19 rebound in patients treated with Paxlovid did not differ from those treated with Molnupiravir. In conclusion, the study confirmed that this rebound phenomenon is not unique to Paxlovid, as both drugs showed increased rates of rebound over time.   

Since the start of the COVID-19 pandemic, more potential treatments and vaccines have emerged to improve patient safety and outcomes. About 1.2 million people have died from COVID-19 as of October, 2022, totaling to over 6.5 million people who have died from the virus since the beginning of the pandemic.⁹ The FDA’s approval allowing pharmacists to prescribe Paxlovid is not only a big step for pharmacists, but also increases the accessibility and pace at which patients can recover from COVID-19. Some pharmacists have shown hesitancy in prescribing Paxlovid, whether it be due to the possibility of rebound COVID-19 or to difficulty in obtaining appropriate patient health records. Regardless, the FDA’s approval for pharmacists to prescribe Paxlovid has emphasized the substantial impact pharmacists have been able to make within the past couple years of the pandemic. 

References

1. Coronavirus (COVID-19) update: FDA authorizes pharmacists to prescribe paxlovid with certain limitations. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements/coronavirus-covid-19-update-fda-authorizes-pharmacists-prescribe-paxlovid-certain-limitations. Published July 6, 2022. Accessed September 13, 2022.  
2. Expanding access to covid 19 therapeutics. ASPR. https://www.phe.gov/Preparedness/legal/prepact/Pages/PREPact-NinethAmendment.aspx. Published September 2021. Accessed September 13, 2022. 
3. Cavazzoni, P. (2022). PAXLOVID EUA Letter of Authorization. https://www.fda.gov/media/155049/download 
4. Paxlovid [package insert]. New York, NY 10017: Pfizer Inc.; Sep, 2022. 
5. Weiland, N. (2022, April 26). With supply more abundant, pharmacies struggle to use up Covid Pills. The New York Times. Accessed October 4, 2022, from https://www.nytimes.com/2022/04/26/us/politics/paxlovid-test-to-treat.html 
6. Power, E. (2022). PAXLOVID Important Prescribing and Dispensing Information. https://www.fda.gov/media/155071/download 
7. Guentez, S. (2022, July 29). Local pharmacies not prescribing COVID-19 treatment drugs yet but have them in stock. Santa Barbara & Goleta Local News. Accessed October 4, 2022, from https://www.noozhawk.com/article/pharmacists_prescribe_paxlovid_covid_19_treatment_santa_barbara 
8. Berger, N. A., Davis, P. B., Kaelber, D. C., Volkow, N. D., & Xu, R. (2022). COVID-19 rebound after Paxlovid and Molnupiravir during January-June 2022. medRxiv: the preprint server for health sciences, 2022.06.21.22276724. https://doi.org/10.1101/2022.06.21.22276724 
9. Coronavirus worldwide graphs. Worldometer. (n.d.). Accessed October 4, 2022, from https://www.worldometers.info/coronavirus/coronavirus-death-toll/ 

Published by Rho Chi Post