This large-scale post-marketing surveillance study (163 sites; February 2022-May 2023) evaluated the real-world safety and effectiveness of a newly initiated nirmatrelvir plus ritonavir combination for patients with COVID-19 in Japan. The current study reports the safety evaluation. The observation period was 28 days after the last day of administration. The safety analysis set comprised 2829 patients (mean standard deviation age, 63.1 18.0 years; mild COVID-19, 80.8%; ≥1 risk factor for progression to severe COVID-19, 97.3%). The most common reason for discontinuing follow-up was symptom improvement (17.1%). Adverse drug reactions (ADRs) were observed in 423 (15.0%) patients (incidence %): dysgeusia (6.7%), diarrhea (2.6%), taste disturbance (1.5%), nausea (1.2%), vomiting (0.5%), decreased appetite (0.5%), and rash (0.5%). The median times to onset and recovery of these ADRs were 1-2 days and 2-6 days, respectively. Serious ADRs were observed in 6 patients (0.2%). No new safety signals were observed. The study showed that nirmatrelvir plus ritonavir was well tolerated in Japanese patients with COVID-19 in a real-world clinical setting. ClinicalTrials.gov number: NCT05263908.
Murata et al. (Thu,) studied this question.