Morning vs. evening administration of antiviral therapy in COVID-19 patients. A preliminary retrospective study in Ferrara, Italy.

OBJECTIVE: At the end of 2019, the Novel Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), spread rapidly from China to the whole world. Circadian rhythms can play crucial role in the complex interplay between viruses and organisms, and temporized schedules (chronotherapy) have been positively tested in several medical diseases. We aimed to compare the possible effects of a morning vs. evening antiviral administration in COVID patients.

PATIENTS AND METHODS: We retrospectively evaluated all patients admitted to COVID internal medicine units with confirmed SARS-CoV-2 infection, and treated with darunavir-ritonavir (single daily dose, for seven days). Age, sex, length of stay (LOS), pharmacological treatment, and timing of antiviral administration (morning or evening), were recorded. Outcome indicators were death or LOS, and laboratory parameters, e.g., variations in C-reactive protein (CRP) levels, ratio of arterial oxygen partial pressure (PaO2, mmHg) to fractional inspired oxygen (FiO2) (PaO2/FiO2), and leucocyte count.

RESULTS: The total sample consisted of 151 patients, 33 (21.8%) of whom were selected for antiviral treatment. The mean age was 61.8±18.3 years, 17 (51.5%) were male, and the mean LOS was 13.4±8.6 days. Nine patients (27.3%) had their antiviral administration in the morning, and 24 (72.7%) had antiviral administration in the evening. No fatalities occurred. Despite the extremely limited sample size, morning group subjects showed a significant difference in CRP variation, compared to that in evening group subjects (-65.82±33.26 vs. 83.32±304.89, respectively, p<0.032). No significant differences were found for other parameters.

CONCLUSIONS: This report is the first study evaluating temporized morning vs. evening antiviral administration in SARS-CoV-2 patients. The morning regimen was associated with a significant reduction in CRP values. Further confirmations with larger and multicenter samples of patients could reveal novel potentially useful insights.