Paxlovid: Reducing the Risk of Hospitalization, Mortality

Investigators from Mass General Brigham reported that patients taking nirmatrelvir plus ritonavir (Paxlovid) within the early onset of COVID-19 reduced hospitalizations by 40% and deaths by 70%.

The study looked at 44 551 nonhospitalized adults (90.3% with ≥3 vaccine doses) aged 50 years or older with COVID-19 and no contraindications for Paxlovid. Of the participants, 12 541 (28.1%) patients were prescribed Paxlovid, and 32 010 (71.9%) were not. Patients prescribed the antiviral were more likely to be older, have more comorbidities, and be vaccinated.

“To mitigate immortal person-time bias and align with the design of EPIC-HR, only patients who were alive, had not received other authorized treatments for early COVID-19 (molnupiravir, remdesivir, or the anti–SARS-CoV-2 monoclonal antibodies sotrovimab and bebtelovimab), and were not hospitalized through 2 calendar days (day of diagnosis and subsequent day) were included,” the investigators wrote. “Eligibility was assessed and study group was assigned at the end of the second calendar day, and hospitalizations and deaths after that time were considered end points. Patients prescribed nirmatrelvir plus ritonavir or another authorized treatment after 2 calendar days from diagnosis were retained in their originally assigned study group.”

This population cohort study looked at patients from January 1 to July 17 of this year, and the primary outcome was hospitalization within 14 days or death within 28 days of COVID-19 diagnosis.

“Recipients of nirmatrelvir plus ritonavir had lower risk for hospitalization (adjusted risk ratio, 0.60 [CI, 0.44 to 0.81]) and death (adjusted risk ratio, 0.29 [CI, 0.12 to 0.71]),” the investigators wrote.

The study was published in the Annals of Internal Medicine.

“The overall risk for hospitalization or death was already low (1%) after an outpatient diagnosis of COVID-19, but nirmatrelvir plus ritonavir reduced this risk further,” the investigators concluded.

For clinicians, considering the right time to prescribe antivirals for people with COVID-19 or even looking at other respiratory illnesses such as influenza are more a clinician preference than a set guideline. In order to experience therapeutic benefits, prescribing nirmatrelvir plus ritonavir earlier in a patient’s diagnosis may lead to more optimal outcomes. However, the ongoing challenge has been the rebound of COVID-19 symptoms and testing positive several days after taking the antiviral. Thus far, previous studies have shown symptoms to be mild when patients do experience a rebound effect.