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Updated: May 25, 2025

Quantitative Structure-Activity Relationship, Activity Prediction, and Molecular Dynamics of Non-nucleotide Reverse Transcriptase Inhibitors
Published on: May 9, 2025
[Effectiveness and safety of nirmatrelvir + ritonavir in COVID-19. NiRCoV Study]
V M González-Rodríguez1, M J Hernández-Arroyo2, C Rodríguez-Barrueco3
1Centro de Salud de Villoria; Gerencia de Atención Primaria de Salamanca; Unidad de Investigación en Atención Primaria de Salamanca (APISAL); Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, España.
Objective:
To analyze the effectiveness and potential safety concerns of Nirmatrelvir + ritonavir (NMV-r) (Paxlovid®) in adults with mild-moderate COVID-19 disease at high risk of progression.
Design:
Descriptive cross-sectional observational study.
Setting:
Castilla y León, Spain.
Participants:
134 patients ≥18 years old with COVID-19 at high risk of progression to severe disease, who were treated between June and September 2022 with NMV-r.
Main Measurements:
The most relevant drug interactions with concomitant medication were obtained from pharmaceutical validation records. From the monitoring of hospital admissions and deaths in the 28 days following the start of treatment, information regarding the effectiveness of the treatment was obtained.
Results:
57.5% were women, the average age±SD was 69.7±17.1, 68.0% received NMV-r in the first two days of the start of symptoms, 74.6% were at home, and 95.7% were vaccinated. The main risk condition for disease progression was being immunocompromised (74.5%), followed by being >65 years old, vaccinated, but with risk factors (21.2%). A total of 62.9% had relevant interactions, with an average±SD of 1.7±1.0 per patient. 2.2% required hospital admission and 3.0% died.
Conclusions:
NMV-r has been effective in preventing severe forms of COVID-19 and hospital admissions in at-risk populations with a high vaccination rate. The prevalence of potential interactions is high, however, collaboration between family physicians and pharmacists allows NMV-r to be used safely.

