Favipiravir pharmacokinetics in COVID-19 patients with moderate to severe kidney dysfunction: Lessons learned.

OBJECTIVE: There is limited information on favipiravir pharmacokinetics in critically ill patients and no studies on pharmacokinetics in patients with moderate and severe kidney dysfunction. The aim was to determine favipiravir pharmacokinetics (oral, 1,600 mg, q12h on day 1, then 600 mg, q12h for 4 days) in critically ill COVID-19 patients with kidney dysfunction and to compare those with observations reported in healthy adults. MATERIALS AND METHODS: In a descriptive study, blood samples taken from patients meeting the relevant criteria (estimated glomerular filtration rate < 60 mL/min) were collected and analyzed. Analysis of blood samples was done by high performance liquid chromatography (HPLC), and the maximal concentration (Cmax), the time of maximal concentration (tmax), half-life (T1/2) and area under the curve (AUC0-12h) of favipiravir were calculated (WinNonlin) and compared to reported data in healthy subjects after first administration. RESULTS: Based on analysis of samples collected in 7 patients, the Cmax (29.99 vs. 64.5 µg/mL) of favipiravir was decreased, T1/2 (5.8 vs. 4.8 hours) longer, tmax delayed, while total exposure was lower (AUC0-12: 192.53 vs. 446.09 µg/mL) compared to reported data in healthy subjects after first administration. Exposure remained lower up to day 5. CONCLUSION: In patients with kidney dysfunction related to COVID-19, favipiravir did not reach the expected exposure. This may be due to poorer and delayed absorption, and subsequent altered disposition. Population pharmacokinetic and mechanistic studies are needed to better explore the relevant covariates and to determine the optimal dose in these patients, as this drug is likely of relevance for other indications.

Clinical Outcomes and Independent Risk Factors for 90-Day Mortality in Critically Ill Patients with Respiratory Failure Infected with SARS-CoV-2: A Multicenter Study in Turkish Intensive Care Units.

BACKGROUND: There are limited data on the long-term outcomes of COVID-19 from different parts of the world. AIMS: To determine risk factors of 90-day mortality in critically ill patients in Turkish intensive care units (ICUs), with respiratory failure. STUDY DESIGN: Retrospective, observational cohort. METHODS: Patients with laboratory-confirmed COVID-19 and who had been followed up in the ICUs with respiratory failure for more than 24 hours were included in the study. Their demographics, clinical characteristics, laboratory variables, treatment protocols, and survival data were recorded. RESULTS: A total of 421 patients were included. The median age was 67 (IQR: 57-76) years, and 251 patients (59.6%) were men. The 90-day mortality rate was 55.1%. The factors independently associated with 90-day mortality were invasive mechanical ventilation (IMV) (HR 4.09 [95% CI: [2.20-7.63], P < .001), lactate level >2 mmol/L (2.78 [1.93-4.01], P < .001), age ≥60 years (2.45 [1.48-4.06)], P < .001), cardiac arrhythmia during ICU stay (2.01 [1.27-3.20], P = .003), vasopressor treatment (1.94 [1.32-2.84], P = .001), positive fluid balance of ≥600 mL/day (1.68 [1.21-2.34], P = .002), PaO2/FiO2 ratio of ≤150 mmHg (1.66 [1.18-2.32], P = .003), and ECOG score ≥1 (1.42 [1.00-2.02], P = .050). CONCLUSION: Long-term mortality was high in critically ill patients with COVID-19 hospitalized in intensive care units in Turkey. Invasive mechanical ventilation, lactate level, age, cardiac arrhythmia, vasopressor therapy, positive fluid balance, severe hypoxemia and ECOG score were the independent risk factors for 90-day mortality.