Clinical rebound after treatment with nirmatrelvir/ritonavir in COVID-19

• Published in: BMC infectious diseases 2024-09, Vol.24 (1), p.963-8, Article 963
• Main Authors: Camp, Daniel, Caputo, Matthew, Echevarria, Fabiola Moreno, Achenbach, Chad J
• Format: Article
• Language: English
• Subjects: Adult; Aged; Anti-viral; Antigens; Antiviral agents; Antiviral Agents - therapeutic use; Case reports; Cohort analysis; COVID-19; COVID-19 - epidemiology; COVID-19 Drug Treatment; COVID-19 vaccines; Diseases; Dosage and administration; Drug dosages; Electronic health records; Electronic medical records; Emergency medical care; FDA approval; Female; Females; Health aspects; Health services; Humans; Indazoles - therapeutic use; Infections; Lactams; Leucine; Male; Medical colleges; Medical records; Medical research; Medicine, Experimental; Middle Aged; Morbidity; Nirmatrelvir/ritonavir; Nitriles; Patient compliance; Patients; Physiological aspects; Proline; Race; Rebound; Recurrence; Relapse; Retrospective Studies; Ritonavir; Ritonavir - therapeutic use; SARS-CoV-2; Severe acute respiratory syndrome coronavirus 2; Statistical analysis; Telemedicine; Treatment Outcome; Vaccination; Viral diseases
• ISSN: 1471-2334; 1471-2334
• DOI: 10.1186/s12879-024-09842-8

Nirmatrelvir/ritonavir (NM/r) is a safe and effective oral antiviral therapeutic used for treatment of mild-to-moderate COVID-19. Case reports described a clinical rebound syndrome whereby individuals experience a relapse of symptoms shortly after completing successful treatment. There is a lack of information on frequency of COVID-19 rebound after NM/r in routine clinical care, contributing factors, and clinical outcomes. We reviewed electronic medical records to verify COVID-19 diagnosis, symptoms, and treatment with NM/r from January-June 2022. We defined COVID-19 clinical rebound as clear improvement in symptoms followed by recurrence or worsening of symptoms within 30 days of a five-day course of NM/r. We studied 268 adults with median age 57 (IQR 47, 68), 80% White race, 85% non-Hispanic ethnicity, 55% female, 80% vaccinated and boosted against SARS-CoV-2, and 68% with any co-morbidity. Sixteen (6.0%) of studied patients were determined to have COVID-19 clinical rebound. The median time from starting NM/r to rebound was 11 days (IQR 9, 13). Notable demographic and clinical factors with higher proportion (not statistically significant) among COVID-19 rebound patients were female sex (75% rebound vs. 54.5% no rebound), Black race (12.5% rebound vs. 4.9% no rebound), presence of at least one co-morbidity (81.3% rebound vs. 67.5% no rebound), and lack of prior SARS-CoV-2 infection (100% rebound vs. 92.9% no rebound). Only one patient (6.25%) was hospitalized after COVID-19 rebound. COVID-19 clinical rebound after treatment with NM/r is mild with favorable outcomes and more common than previously reported from real-world clinical care studies.