ABSTRACT
Background and Importance On March 28th 2022, nirmatrelvir/ ritonavir was marketed in Spain. The Spanish Agency for Medicines and Medical Devices (AEMPS) established criteria to prioritise its administration in patients at high risk of progression to severe COVID. Data regarding the effectiveness and safety of nirmatrelvir in preventing severe coronavirus disease outcomes are limited. Aim and Objectives To assess the effectiveness and safety of nirmatrelvir/ritonavir in patients at high risk for severe COVID-19. Material and Methods Prospective descriptive study from April to August 2022 of patients treated with nirmatrelvir/ritonavir. Sociodemographic variables, vaccination status, hospital admission, high risk factors for progression and concomitant treatment were recorded. Readmissions were recorded within 30 days of the end of antiviral treatment. Results 53 patients were included with a mean age of 64 years, 51% women and 49% men. 57% were vaccinated with 3 doses, 17% with 2 doses, 9% with 4 doses, 6% with 1 dose and 11% were not vaccinated. 34% (18/53) were hospitalised at the time of initiation of treatment. The most prevalent high-risk criteria were: 24% active treatment with myelotoxic chemotherapy, 21% treatment in the previous 6 months with anti-CD20 drugs, 14% over 80 years vaccinated with some risk factor for progression, 7% patients with onco-haematological treatment and 7% in treatment in the previous 3 months with inhibitors of the proteinkinase. 3 treatments were performed off-label for persistent covid. The mean number of days from the onset of symptoms to the start of treatment was 1.6 days. 23% of patients required dose adjustment due to renal impairment. 53% required adjustment of chronic treatment for interactions, mainly with metamizole, statins, fentanyl and diazepam. 2 patients received remdesivir and sotrovimab, 2 remdesivir and another two sotrovimab. 4 (7%) patients were readmitted within 30 days after the end of treatment with nirmatrelvir ritonavir, 1 of them with persistent covid. One patient stopped treatment for hives. Conclusion and Relevance Nirmatrelvir ritonavir has been shown to be a safe and effective drug in high-risk patients of progression to severe covid.