Acute pulmonary emboli following rebound phenomenon after Nirmatrelvir/Ritonavir treatment for COVID-19.

The return of COVID-19 symptoms after Nirmatrelvir/Ritonavir (Nm/R) treatment is being increasingly reported. Limited evidence suggests most cases of rebound symptoms are mild and do not require further intervention. Here we present a male veteran reporting rebound symptoms who was found to be hypoxic with pulmonary emboli. Our case highlights the need to evaluate known complications of SARS-CoV-2 including venous thromboembolism in patients reporting recurring symptoms. Further, cases of severe rebound phenomenon should continue to be reported by clinicians to better appreciate the use of the Nm/R during the Omicron wave and among vaccinated persons.