Target Attainment and Population Pharmacokinetics of Nirmatrelvir/Ritonavir in Critically Ill Adult Patients.

Background: The population pharmacokinetics of nirmatrelvir/ritonavir (NIR/RIT) has not yet been described for critically ill adult patient. Purpose: This was a prospective observational population pharmacokinetic study of nirmatrelvir/ritonavir (NIR/RIT) in critically ill adult patients and identify optimal dosing regimens. Patients and Methods: The prescription of NIR/RIT is determined by the attending physician and ranges from 150mg/100mg to 300mg/100mg twice a day. Two to three serial blood samples were collected for each patient after the second doses. We developed and validated PK model for plasma NIR and plasma RIT. Monte Carlo dosing simulations were performed to assess target attainment. Results: We analyzed 89 plasma samples from 31 adult patients. The data were best described by a one-compartment model. Among the covariates tested on pharmacokinetic parameters, creatinine clearance (CrCL) and area under curve (AUC) of RIT had a significant effect on apparent clearance (CL/F) of NIR. Mean (SD) parameters estimates for the absorption rate constant (Ka), apparent distribution (V/F) and CL/F were 0.42 (0.10) h-1. 36.5 (8.5) L, 3.6 (0.26) L/h, respectively. Dosing simulations showed that the target in vitro 90% effective concentration (EC90) was more likely to be achieved twice a day than once a day at the same daily dose of NIR. High CrCL, low AUC of RIT were associated with a reduced likelihood of NIR reaching the target EC90. Conclusion: Based on our dosing simulations, the initial dosage of NIR/RIT was 300mg/100mg twice a day in critically ill patients with CrCL>45 mL/min; When CrCL in critically ill patients is between 15 and 45 mL/min, NIR/RIT is 150mg/100mg twice a day. The maintenance dose is adjusted according to CrCL and AUC of RIT, with the dosages varying between 75mg/100mg and 300mg/100mg.

Population pharmacokinetics of nirmatrelvir/ritonavir in critically ill Chinese COVID-19 patients and recommendations for medication use: a two-center retrospective study.

BACKGROUND: This study aimed to establish population pharmacokinetics (PPK) models of nirmatrelvir/ritonavir in critically ill Chinese patients with the coronavirus disease 2019 (COVID-19) infection, explore factors affecting the pharmacokinetics (PK) of nirmatrelvir/ritonavir. METHODS: A total of 285 serum samples and clinical data were collected from 152 patients. The PPK models of nirmatrelvir/ritonavir were analyzed using nonlinear mixed-effect modeling (NONMEM) approach. The optimal dosing regimen for patients with different renal function was determined using Monte Carlo simulations. RESULTS: The population typical values of apparent clearance (CL/F) and apparent volume of distribution (V/F) of nirmatrelvir were 2.26 L/h and 15.3 L, respectively. Notably, creatinine clearance (CrCL) significantly influenced the PK variation of nirmatrelvir. Monte Carlo simulations suggested that patients with mild-to-moderate renal impairment experienced a 22.0-59.9% increase in the area under the curve (AUC) when they were administered a standard dose of nirmatrelvir compared to those with normal renal function. The AUC in patients with severe renal impairment after administration of 150 mg q12h nirmatrelvir was similar to that in patients with normal renal function after administration of 300 mg q12h nirmatrelvir. CONCLUSIONS: PPK modeling and simulation provided a reference for the rational clinical application of nirmatrelvir/ritonavir in critically ill Chinese patients.

Clinical rebound after treatment with nirmatrelvir/ritonavir in COVID-19.

BACKGROUND: Nirmatrelvir/ritonavir (NM/r) is a safe and effective oral antiviral therapeutic used for treatment of mild-to-moderate COVID-19. Case reports described a clinical rebound syndrome whereby individuals experience a relapse of symptoms shortly after completing successful treatment. There is a lack of information on frequency of COVID-19 rebound after NM/r in routine clinical care, contributing factors, and clinical outcomes. METHODS: We reviewed electronic medical records to verify COVID-19 diagnosis, symptoms, and treatment with NM/r from January-June 2022. We defined COVID-19 clinical rebound as clear improvement in symptoms followed by recurrence or worsening of symptoms within 30 days of a five-day course of NM/r. RESULTS: We studied 268 adults with median age 57 (IQR 47, 68), 80% White race, 85% non-Hispanic ethnicity, 55% female, 80% vaccinated and boosted against SARS-CoV-2, and 68% with any co-morbidity. Sixteen (6.0%) of studied patients were determined to have COVID-19 clinical rebound. The median time from starting NM/r to rebound was 11 days (IQR 9, 13). Notable demographic and clinical factors with higher proportion (not statistically significant) among COVID-19 rebound patients were female sex (75% rebound vs. 54.5% no rebound), Black race (12.5% rebound vs. 4.9% no rebound), presence of at least one co-morbidity (81.3% rebound vs. 67.5% no rebound), and lack of prior SARS-CoV-2 infection (100% rebound vs. 92.9% no rebound). Only one patient (6.25%) was hospitalized after COVID-19 rebound. CONCLUSIONS: COVID-19 clinical rebound after treatment with NM/r is mild with favorable outcomes and more common than previously reported from real-world clinical care studies.

Treatment of persistent coronavirus disease 2019 (COVID-19) in a B cell acute lymphoblastic leukemia patient with using nirmatrelvir/ritonavir extended course: A case report.

Patients with hematological malignancies are at increased risk of persistent coronavirus disease 2019 (COVID-19) infection, a unique clinical condition, for which the optimal treatment is unknown. Here we report a case of persistent COVID-19 in acute lymphoblastic leukemia (ALL) patient who successfully responded to extended course nirmatrelvir/ritonavir.

Sustainable and technically smart spectrophotometric determination of PAXLOVID: a comprehensive ecological and analytical performance rating.

The Food and Drug Administration (FDA) authorized the administration of ritonavir (RIT)-boosted nirmatrelvir (NMV) on May 25, 2023, for the treatment of mild to moderate COVID-19 in patients who are at high risk of developing severe COVID-19. In accordance with sustainability and environmental friendliness, simple, eco-friendly, and sustainable spectrophotometric methods were established for concurrently estimating RIT and NMV in newly launched copackaged pills. The suggested solutions for resolving the spectral overlap between RIT and NMV involve the following mathematical methods: the first derivative method (1D), second derivative method (2D), and dual-wavelength zero-order method (DWZ). When ethanol was used as a green dilution solvent, the linearity range was adjusted (10-250 µg/mL) for both drugs. The procedures resulted in a high correlation coefficient (not less than 0.9996) and satisfactory levels of detection and quantification. Additionally, method validation was performed in accordance with International Council for Harmonization norms. Moreover, a detailed ecological and sustainability evaluation protocol was established to confirm the greenness and whiteness of the methods. Finally, the proposed method, along with previously reported methods for analysing NMV and RIT, were reviewed analytically and ecologically.

A Real-World Retrospective Study on the Efficacy and Safety of Four Antiviral Drugs for Hospitalized COVID-19 Patients: Nirmatrelvir/Ritonavir, Simnotrelvir/Ritonavir, Molnupiravir and Azvudine.

Purpose: This retrospective study aims to compare the effectiveness and safety of four oral antiviral drugs including Simnotrelvir/Ritonavir, Nirmatrelvir/Ritonavir, Azvudine and Molnupiravir in hospitalized patients with Coronavirus Disease 2019 (COVID-19) in a real-world setting, providing evidence to guide clinical practice against COVID-19. Patients and Methods: Patients with mild or moderate COVID-19 hospitalized at Wuxi City's Second People's Hospital during December 2022 to June 2023 were included in this study. Patients were grouped by the antiviral drug received. The primary endpoint was the length of hospital stay. Patients were further divided into subgroups for stratified analysis, considering age, timing of medication, and drug mechanisms, to explore whether these factors could influence the treatment efficacy. Results: Of the enrolled 195 patients receiving any treatment, 42 received Nirmatrelvir/Ritonavir, 33 received Molnupiravir, 81 received Simnotrelvir/Ritonavir, and 39 received Azvudine. Patients in Nirmatrelvir/Ritonavir and Simnotrelvir/Ritonavir groups had significantly shorter hospital stays compared to those in Azvudine group (P < 0.05). No significant difference was observed in hospital stays between those initiating antiviral therapy within or more than five days after symptom onset (P = 0.1109). Among patients with comorbidities, the Nirmatrelvir/Ritonavir and Simnotrelvir/Ritonavir group showed shorter hospital stays than the Azvudine group (P < 0.05). No serious treatment-related adverse events were observed across the groups. Conclusion: In this retrospective study, Nirmatrelvir/Ritonavir and Simnotrelvir/Ritonavir exerts stronger potency on reducing duration of hospital stays in hospitalized patient with COVID-19, suggestive of a better choice for antiviral therapy. Patients who fail to take antiviral drugs in time after symptom onset would still benefit from these antiviral regimens. Additional well-designed clinical trials with large sample size are still needed to further confirm the effectiveness of these antivirals.

Cardiovascular Drug Interactions with Nirmatrelvir/Ritonavir for COVID-19: Considerations for Daily Practice.

Cardiovascular disease is associated with progression to severe COVID-19 and patients with the condition are among those in whom early antiviral therapy should be warranted. The combination of nirmatrelvir/ritonavir (Paxlovid®) has been approved for clinical use by the Food and Drug Administration and European Medicines Agency. Because patients with cardiovascular disease are often on polypharmacy, physicians need to be aware of potential drug-drug interactions (DDIs) when treating COVID-19 with nirmatrelvir/ritonavir. Guidance is given for avoiding DDIs, emphasising that preventing and managing potential DDIs with nirmatrelvir/ritonavir requires thorough assessment and knowledge. The present review summarises the clinical pharmacology of nirmatrelvir/ritonavir and provides details on potential DDIs with a focus on daily practice in patients with cardiovascular disease. Particular attention is needed for drugs that are predominantly metabolised by cytochrome P450 3A4, are substrates of P-glycoprotein and have a narrow therapeutic index. Proper management of potential DDIs must balance the benefit of nirmatrelvir/ ritonavir to prevent severe disease with the risk of serious adverse events.

Evaluation of the drug-drug interactions management system for appropriate use of nirmatrelvir/ritonavir: a retrospective observational study.

PURPOSE: While nirmatrelvir/ritonavir (NMV-r) has been positioned as a first-line treatment for mild to moderate COVID-19, it has multiple and significant drug-drug interactions (DDIs). The use of NMV-r in Japan has been limited compared to the United States. This study aimed to describe the distribution of DDIs with NMV-r and their management in patients with COVID-19 under the control of a management system for the appropriate use of NMV-r. METHODS: A retrospective observational study was conducted at a Japanese university hospital. The management system included a flowchart for selecting antivirals and a list for reviewing DDI management, based on the National Institutes of Health guidelines and the guidance of the Japanese Society of Pharmaceutical Health Care and Sciences. Patients with mild to moderate COVID-19 and prescribed NMV-r or molnupiravir (MOV) were included. The primary outcome was DDI management practices, including the selected COVID-19 medications. The secondary outcome included the distribution of DDI classification and the 30-day all-cause mortality. RESULTS: This study included 241 patients (median age of 60 years, 112 [46.5%] females), of whom 126 and 115 received NMV-r and MOV, respectively. Of the 241 patients, 145 (60.2%) received concomitant medications that have DDIs with NMV-r. All 30 patients with severe renal impairment or insufficient details on concomitant medications received MOV. Forty-nine patients with concomitant medications required alternative COVID-19 therapy consideration due to DDIs, of whom 42 (85.7%) patients received MOV. Eighty-one patients had concomitant medications requiring temporary adjustment, of whom 44 (54.3%) patients received NMV-r, and 42 of these patients temporarily adjusted these concomitant medications. Five patients with concomitant medications that can continued by monitoring the effects/adverse effects, of whom 4 (80.0%) patients received NMV-r. Seventy-six patients without concomitant medications requiring DDI management, of whom 71 (93.4%) patients received NMV-r. The 30-day all-cause mortality for eligible patients was 0.9% [95% confidence interval, 0.1-3.1]. CONCLUSIONS: Most patients received appropriate antivirals according to the classification of DDIs, and most patients with concomitant medications requiring temporary adjustment received the recommended DDI management. Our management system is effective in promoting the use of NMV-r in the appropriate patients and managing problematic DDIs.

Prevalence of Potential Drug Interactions With Direct-Acting Antivirals for COVID-19 Among Hospitalized Patients.

PURPOSE: Clinicians consider polypharmacy, comorbidities, and other factors including the potential for drug-drug interactions (DDIs) when evaluating therapeutic options for specific clinical diagnoses. Contemporary treatment for coronavirus disease 2019 (COVID-19) includes direct-acting antivirals (DAAs). We sought to characterize patients' characteristics, comorbidities, and medications received during their hospitalization for COVID-19 and quantify potential DDIs that clinicians consider in selecting appropriate DAAs. METHODS: Patients hospitalized with a primary diagnosis of COVID-19 between May 2020 and December 2022 from the PINC AI Healthcare Database were identified. Medications administered during the hospitalization with the potential to cause DDIs with nirmatrelvir/ritonavir, remdesivir, or molnupiravir (per the Emergency Use Authorization factsheet or package insert) were assessed. For DDIs with nirmatrelvir/ritonavir, medications are categorized as "Contraindicated," "Avoid Concomitant Use," or "Other DDIs" (includes recommendation for dose modification or clinical and laboratory monitoring). For remdesivir, coadministration with chloroquine phosphate and hydroxychloroquine sulfate was not recommended. For molnupiravir, no drugs are listed as having potential DDIs. In a subset of patients, a multivariable logistic regression model was used to examine the association between documented patient/hospital characteristics and the likelihood of being "Contraindicated" to receive nirmatrelvir/ritonavir. FINDINGS: Of the 788,238 patients hospitalized for COVID-19 in 920 hospitals, 53% were ≥ 65 years old, and 31% had Charlson Comorbidity Index (CCI) ≥ 3. During the study period, about half of the patients received medications categorized as "Contraindicated" (11%) and/or "Avoid Concomitant Use" (41%) with nirmatrelvir/ritonavir. The frequency of administered drugs was higher in those aged ≥ 65 years (68%), CCI ≥ 3 (78%), with high-risk underlying conditions (55%). About 1% of patients received medications that were not recommended to be coadmistered with remdesivir. Among a subset of patients hospitalized for COVID-19 in 2022, those who were older, had higher CCI, high-risk underlying conditions, severe hepatic impairment, Medicare insurance, and hospitalized in larger hospitals were significantly more likely to be categorized as "Contraindicated" when considering nirmatrelvir/ritonavir as a therapeutic option to manage COVID-19. IMPLICATIONS: A significant proportion of patients hospitalized for COVID-19 receive medications for other conditions that have the potential to result in DDIs with DAAs; most predominantly with nirmatrelvir/ritonavir, a strong CYP3A enzyme inhibitor, fewer with remdesivir, and none with molnupiravir. Higher age and comorbidity burden were significantly associated with a higher likelihood of receiving medications that are "Contraindicated" with nirmatrelvir/ritonavir. In the evolving COVID-19 era, these findings provide insights into patients hospitalized for COVID-19, and the polypharmacy evaluations that clinicians may encounter when selecting among DAAs to manage COVID-19.

A Systematic Review of Nirmatrelvir/Ritonavir and Molnupiravir for the Treatment of Coronavirus Disease 2019.

Background: To address the need for treatments for patients with coronavirus disease 2019 (COVID-19), 3 therapies have been given either full approval or Emergency Use Authorization. These were based on randomized data showing a reduction in deaths/hospitalization, but since then, circulating viral strains and population immunity have changed. Methods: We searched PubMed, Web of Science, Embase, and ClinicalTrials.gov for clinical trials testing nirmatrelvir/ritonavir and molnupiravir for COVID-19. We identified all trials testing nirmatrelvir/ritonavir and molnupiravir in patients with COVID-19 and assessed the pooled efficacy in a meta-analysis. We calculated pooled estimates of hospitalization and death in patients with COVID-19 and the number of studies with published/reported data. Results: Of the 23 studies found, 11 tested nirmatrelvir/ritonavir, 10 tested molnupiravir, and 2 tested both agents. The pooled estimate in reducing deaths and hospitalization for molnupiravir was 0.62 (95% confidence interval [CI], 0.15-2.53), and the pooled estimate for nirmatrelvir/ritonavir was 0.33 (95% CI, 0.03-3.35). The 1 nirmatrelvir/ritonavir trial that reported significant improvements tested people who were predominantly infected with earlier COVID-19 variants, whereas the 2 null trials were tested in people infected with more recent variants. The 2 positive molnupiravir trials included participants primarily with the Delta variant, whereas the null trials were tested later, against more recent variants. Conclusions: While early trial data show effectiveness of these therapies, the overall pooled effects are nonsignificant, suggesting that recommendations and use of approved oral COVID-19 treatment therapies need to be reevaluated in the context of current viral strains and population immunity.

Paxlovid (Nirmatrelvir/Ritonavir)-Induced Tacrolimus Toxicity in Organ Transplant Recipients - A Review on Drug Interactions Involving CYP3A Enzymes.

Paxlovid (nirmatrelvir/ritonavir) is the first oral therapy approved by the US FDA to treat patients with mild-to-moderate COVID-19. Our current review focuses on clinical data related to tacrolimus toxicity induced by Paxlovid currently available. A number of online databases, including LitCovid, Scopus, Web of Science, Embase, EBSCO host, Google Scholar, Science Direct, and the reference lists were searched to identify articles related to Paxlovid-induced tacrolimus toxicity, using keywords, like drug interactions, Paxlovid, ritonavir, nirmatrelvir, tacrolimus, pharmacokinetic interactions, and CYP3A. Tacrolimus is a substrate of CYP3A enzymes and ritonavir of Paxlovid has been identified as a potent inhibitor of CYP3A enzymes. Hence, Paxlovid can inhibit the CYP3A-mediated metabolism of tacrolimus, resulting in elevated plasma concentrations of tacrolimus and toxicity. A number of case reports and case series have been published to highlight the association of Paxlovid and tacrolimus toxicity in transplant recipients with COVID-19 infection. Various recommendations have been proposed to prevent and mitigate the adverse events related to the DDI of Paxlovid and tacrolimus. Transplant physicians should be aware of this DDI and collaborate with clinical pharmacists on this issue.

The effectiveness of nirmatrelvir/ritonavir regimen in hospitalized renal transplant patients with prolonged COVID-19 infection: a multicenter clinical experience.

OBJECTIVES: Effectiveness of nirmatrelvir/ritonavir (NR) in kidney transplant recipients (KTRs) infected COVID-19 for more than 5 days has not been evaluated. METHODS: In this multicenter retrospective study, 85 KTRs with COVID-19 were enrolled, including 50 moderate, 21 severe, and 14 critical patients. RESULTS: The median time from onset to starting NR treatment was 14 (IQR, 11-19) days. Before NR treatment, 96.5% patients reduced use of antimetabolites. They also stopped using calcineurin inhibitors (CNI) 12-24 hours before NR treatment, with CNI concentrations well-controlled during NR treatment. The use of intravenous corticosteroids increased with COVID-19 severity. The median time to reach viral negative conversion was 5 (IQR, 4-8) days for all patients. For moderate and severe COVID-19 patients, they had a low rate of ICU admission (1.4%), exacerbation requiring upgraded oxygen therapy (5.6%), and dialysis (2.8%); no intubation and mechanical ventilation, and no deaths were observed. Patients with critical COVID-19 had a low mortality rate (7.1%). CONCLUSIONS: A regimen including NR for clearing SARS-CoV-2 along with reducing immunosuppressants and using intravenous corticosteroids is associated with lower rates of exacerbation and mortality in KTRs who have moderate to critical SARS-CoV-2 infection and the virus still present after 5 days.

Hyphenating sustainability with chemometrics in chromatographic analysis of COVID combo therapy, nirmatrelvir and Molnupiravir, in presence of their overlapping degradation products; blue-green dual evaluation tools.

Our manuscript managed to hyphenate the novelty and sustainability in one method. A novel combination of molnupiravir (MNP) and nirmatrelvir (NTV) was found to be a potential symbiotic therapy against SARS-CoV-2. Yet, there is no analytical method published for either determination or stability investigation of this combination simultaneously. So, the proposed HPLC technique focused on determination of MNP and NTV in presence of their degradation products. The sustainability was achieved in our method by using chemometrics tools to quantify NTV in presence of its co-eluted degradation product (NTV-D) without excessive time and solvent usage for separation (run time 5 min.). Moreover, the linearity parameters of both MNP and NTV, including correlation coefficient, LOD and LOQ, have been enhanced significantly after chemometrics treatment through convolution of the resultant derivative curves using trigonometric Fourier function. For example, LOQ of MNP decreased from 3.53 to 0.31 µg/mL and for NTV, LOQ decreased from 4.98 to 2.10 µg/mL after chemometrics treatment. The stability results of the proposed method indicates that no interaction or change in stability behavior of both drugs when co-administered with each other. Thus, this can be used as an empirical basis to initiate clinical trials of this combination for the treatment of COVID-19 patients. Additionally, in order to determine the impact of chemometric methods in minimizing analysis time and reducing solvent, energy, and waste consumption, our chemometric methodology is evaluated in terms of greenness and blueness (dichromic assessment) using AGREE and BAGI, respectively. Besides, the method sustainability using Hexagon was evaluated.

Paxlovid for the treatment of COVID-19: a systematic review and meta-analysis.

INTRODUCTION: Paxlovid (nirmatrelvir/ritonavir) is a new oral antiviral drug that is used for coronavirus disease 2019 (COVID-19) and is administered to patients with mild to moderate disease for five consecutive days. This meta-analysis aimed to evaluate the efficacy of Paxlovid in COVID-19 patients. METHODOLOGY: PubMed, Embase, Cochrane Library, and Web of Science databases were searched to identify relevant publications up to 9 March 2023. Three randomized controlled trial (RCT) studies, one prospective cohort study, and 25 retrospective cohort studies were identified for the meta-analysis. RESULTS: There was a significant difference between the Paxlovid and control groups in terms of hospitalization (RR = 0.53; 95% CI: 0.24-0.69, p < 0.001), all-cause mortality (RR = 0.36; 95% CI: 0.27-0.50, p < 0.001), hospitalization or death (RR = 0.50; 95% CI: 0.37-0.67, p < 0.001), intensive care unit admission (RR = 0.45; 95% CI: 0.27-0.73, p = 0.001), and emergency department visits (RR = 0.67; 95% CI: 0.54-0.83, p < 0.001). However, no significant difference was found between the two groups in terms of COVID-19 rebound (OR = 1.18; 95% CI: 0.82-1.68, p = 0.37). In addition, the Paxlovid group had a significantly shorter hospital length of stay (weighted mean difference WMD = -1.11; 95% CI, -1.81, -0.41; I2 > 50%, p < 0.05), and polymerase chain reaction negative conversion time (WMD = -2.75; 95% CI, -3.60, -1.89, I2 > 50%, p < 0.05) than that of the control group. CONCLUSIONS: Paxlovid can be considered an effective therapeutic agent for treating patients with COVID-19.

Nirmatrelvir/Ritonavir (Paxlovid) Use Among Individuals at Risk of Severe COVID-19: An Analysis of the National COVID Cohort Collaborative (N3C).

PURPOSE: Paxlovid is effective in reducing COVID-19 hospitalization and mortality. This study characterized Paxlovid use and evaluated racial/ethnic disparities over time among community-dwelling adults at high risk of progression to severe COVID-19 disease. METHODS: This retrospective cohort study used the National COVID Cohort Collaborative (N3C) data and included individuals aged 18 years or older diagnosed with COVID-19 between January 2022 and December 2023. The study cohort included nonhospitalized individuals who were at high risk of COVID-19 progression, and selected the first COVID-19 episode in each quarter, including reinfection episodes. Paxlovid use was defined as receiving Paxlovid within ±5 days of a COVID-19 diagnosis. We used descriptive statistics to characterize Paxlovid use overall and by calendar quarter and race/ethnicity. We used a generalized estimating equations (GEE) models to quantify the association of race/ethnicity with Paxlovid use controlling for age, gender, and clinical characteristics. RESULTS: Among 1 264 215 individuals at high risk of disease progression (1 404 607 episodes), Paxlovid use increased from 1.2% in January-March 2022 to 35.1% in October-December 2023. Paxlovid use was more common among non-Hispanic White individuals (23.9%) than non-Hispanic Black (16.5%) and Latinx/e (16.7%) patients. After adjusting age, gender, and clinical characteristics, Paxlovid use was less likely among non-Hispanic Black (odds ratio [OR] 0.69, 95% confidence interval [CI] 0.68-0.70) and Latinx/e (OR 0.72, CI 0.71-0.73) patients than non-Hispanic White patients. CONCLUSIONS: Among a large, diverse cohort of community-dwelling individuals with COVID-19, nearly two out of three eligible individuals did not receive Paxlovid, and minoritized racial/ethnic groups were less likely to use Paxlovid than their non-Hispanic White individuals.

Nirmatrelvir/ritonavir treatment and the risk of post-COVID condition over 180 days in Malaysia.

BACKGROUND: The effect of nirmatrelvir/ritonavir on preventing post-COVID condition (PCC) in the BA4, BA5, and XBB Omicron predominant periods is not well understood. The purpose of this study was to assess how nirmatrelvir/ritonavir treatment affected both PCC and health-related quality of life. METHODS: This retrospective cohort study enrolled 2,524 adults aged 18 years and older who were eligible for nirmatrelvir/ritonavir between July 14 to November 14, 2022. All outcomes were observed from the patient's first visit to the primary health clinic, 1 week, 1 month, 3 months, and 6 months after testing positive for COVID-19. The primary outcome was the presence of PCC. Secondary outcomes included the effects on health-related quality of life, such as walking, bathing and dressing, activities, cause adverse emotions or signs that prevent individuals from leading normal lives over a 180-day observation period. RESULTS: There were no significant differences observed between the nirmatrelvir/ritonavir and those not administered (control group) in terms of PCC symptoms at 3 months (OR 0.71 95% CI 0.31, 1.64) and 6 months (OR 1.30 95% CI 0.76, 2.21). At 3 months, the use of nirmatrelvir/ritonavir was associated with a 26% reduction in symptoms causing negative emotions (OR 0.74 95% CI 0.60, 0.92) and an increased likelihood of symptoms limiting walking (OR 1.58 95% CI 1.10, 2.27). However, there were no significant differences between the nirmatrelvir/ritonavir and the control group in terms of the impact of PCC on health-related quality of life at 6 months. CONCLUSIONS: Our study indicates that the administration of nirmatrelvir/ritonavir does not significantly reduce PCC after 3 months and 6 months in a population with high vaccination coverage.

Comparative analysis of the safety and effectiveness of Nirmatrelvir-Ritonavir and Azvudine in older patients with COVID-19: a retrospective study from a tertiary hospital in China.

Introduction: Numerous studies have explored the treatment outcomes of Nirmatrelvir-Ritonavir and Azvudine in older patients with COVID-19. However, direct comparisons between these two drugs are still relatively limited. This study aims to compare the safety and effectiveness of these two drugs in Chinese older patients with early infection to provide strategies for clinical treatment. Methods: Older COVID-19 patients (age ≥65) hospitalized during the winter 2022 epidemic in China were included and divided into Nirmatrelvir-Ritonavir and Azvudine. Demographics, medication information, laboratory parameters, and treatment outcomes were collected. All-cause 28-day mortality, delta cycle threshold (ΔCt), nucleic acid negative conversion time, and incidence of adverse events were defined as outcomes. Propensity score matching (PSM), Kaplan-Meier, Cox proportional hazards model, subgroup analysis, and nomograms were selected to evaluate the outcomes. Results: A total of 1,508 older COVID-19 patients were screened. Based on the inclusion and exclusion criteria, 1,075 patients were eligible for the study. After PSM, the final number of older COVID-19 patients included in the study was 375, and there were no significant differences in demographic characteristics between the two groups (p > 0.05). Compared to the Azvudine group, the Nirmatrelvir-Ritonavir group showed a higher incidence of multiple adverse events (12.8% vs 5.2%, p = 0.009). The incidence of adverse events related to abnormal renal function was higher in the Nirmatrelvir-Ritonavir group compared to the Azvudine group (13.6% vs 7.2%, p = 0.045). There were no significant differences between the two groups in terms of all-cause 28-day mortality (HR = 1.020, 95% CI: 0.542 - 1.921, p = 0.951), whereas there were significant differences in nucleic acid negative conversion time (HR = 1.659, 95% CI: 1.166 - 2.360, p = 0.005) and ΔCt values (HR = 1.442, 95% CI: 1.084 - 1.918, p = 0.012). Conclusion: Azvudine and Nirmatrelvir-Ritonavir have comparable effectiveness in reducing mortality risk. Azvudine may perform better in nucleic acid negative conversion time and virus clearance and shows slightly better safety in older patients. Further studies with a larger sample size were needed to validate the result.

Persistence of an infectious form of SARS-CoV-2 post protease inhibitor treatment of permissive cells in vitro.

Reports have described SARS-CoV-2 rebound in COVID-19 patients treated with nirmatrelvir, a 3CL protease inhibitor. The cause remains a mystery, although drug resistance, re-infection, and lack of adequate immune responses have been excluded. We now present virologic findings that provide a clue to the cause of viral rebound, which occurs in ∼20% of the treated cases. Persistence of infectious SARS-CoV-2 was experimentally documented in vitro after treatment with nirmatrelvir or another 3CL protease inhibitor, but not with a polymerase inhibitor, remdesivir. This infectious form decayed slowly with a half-life of ∼1 day, suggesting that its persistence could outlive the treatment course to re-ignite SARS-CoV-2 infection as the drug is eliminated. Notably, extending nirmatrelvir treatment beyond 8 days abolished viral rebound in vitro. Our findings point in a particular direction for future investigation of virus persistence and offer a specific treatment recommendation that should be tested clinically.

Curing of chronic hepatitis C combined with coronavirus disease 2019 in a couple over 85 years old: a case series study.

Introduction: Data on the management of patients aged more than 85 years with chronic hepatitis C virus (HCV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequential infections are lacking. Methods: The current study described the management of an older couple aged more than 85 years with these above-mentioned two diseases treated with 12 weeks of sofosbuvir/velpatasvir (Epclusa®) and 5 days of nirmatrelvir/ritonavir (Paxlovid®) sequentially. The effectiveness and safety profiles were closely monitored during therapy and till 9 months posttreatment. Results: In late March 2023, the husband with the main complaint of repeated gingival bleeding and asymptomatic wife were 86 and 85 years old, and had HCV RNA levels of 91,800 and 6,630,000 IU/mL, respectively. On the fourth day of sofosbuvir/velpatasvir treatment, the husband had a moderate headache, and the wife had severe headache and moderate fever and dizziness. We then found that their SARS-CoV-2 test results were positive. After careful consideration, the expert panel decided to treat the couple with oral nirmatrelvir/ritonavir (300 mg/100 mg, twice daily) beginning on the fifth day of sofosbuvir/velpatasvir treatment for 5 days. During the 5 days of nirmatrelvir/ritonavir treatment, the patient's symptoms and signs gradually improved, and the patient was negative for SARS-CoV-2 RNA on the fifth day of nirmatrelvir/ritonavir therapy. Meanwhile, the husband's HCV RNA was not detectable after one week of sofosbuvir/velpatasvir treatment till posttreatment month 9, and his ALT level was normal beginning at week 1 of sofosbuvir/velpatasvir treatment. Moreover, the wife's HCV RNA was not detectable after week 4 of sofosbuvir/velpatasvir treatment till posttreatment month 9. Notably, no other symptoms or signs occurred during the treatment or follow-up period, and other serum biochemical parameters remained stable until 9 months after the discontinuation of sofosbuvir/velpatasvir treatment. Conclusion: The older couple aged more than 85 years with chronic HCV and SARS-CoV-2 sequential infection were safely cured by the sofosbuvir/velpatasvir and nirmatrelvir/ritonavir sequential treatment. Discussion: This study suggested that old age should not be a barrier to HCV/SARS-CoV-2 treatment. Given that the proportion of older HCV-infected patients is increasing, clinical trials of direct-acting antiviral agents should include older HCV-infected individuals.

Proportion of Patients in the United States Who Fill Their Nirmatrelvir/Ritonavir Prescriptions.

INTRODUCTION: Although real-world studies demonstrate that those prescribed nirmatrelvir/ritonavir (and particularly within 5 days of symptom onset) are less likely to experience severe COVID-19 outcomes, prior studies show that only a small fraction of patients with COVID-19 who are eligible for nirmatrelvir/ritonavir receive a prescription. Studies calculating the proportion of nirmatrelvir/ritonavir prescriptions filled and identifying individual- and pharmacy-level correlates of filling nirmatrelvir/ritonavir are lacking. METHODS: This retrospective cohort study included individuals aged ≥ 12 years with a nirmatrelvir/ritonavir prescription ordered at a large national retail pharmacy (December 22, 2021-August 12, 2023). Those taking contraindicated medications were excluded. For those with only one nirmatrelvir/ritonavir prescription ordered, the outcome was whether the prescription was filled (yes/no). In a subanalysis of these individuals, the outcome was whether the prescription was filled within 5 days of symptom onset (yes/no). For those with multiple prescriptions ordered, the outcome was whether > 1 (vs. 0 or 1) prescriptions were filled. A log-binomial regression with generalized estimating equations was used to identify individual (clinical and demographic) and pharmacy-level (percentage of trade area that is non-Hispanic white, urbanicity, US Census region, and tract-level area deprivation index) correlates. RESULTS: A total of 2,103,570 unique nirmatrelvir/ritonavir prescriptions were ordered for 1,985,990 individuals. Among the 95% of individuals prescribed only one nirmatrelvir/ritonavir course, 88% filled their prescription. Among those with > 1 prescription ordered, 77% (82,993/108,411) filled one and 13% (13,662/108,411) filled > 1. Patients ≥ 50 years of age and those with documented high-risk conditions were slightly more likely to fill prescriptions, regardless of whether one or multiple courses were ordered. Individuals with cancer, asthma, or taking corticosteroids or immunosuppressive medications were more likely to fill multiple prescriptions. CONCLUSIONS: Most patients filled their nirmatrelvir/ritonavir prescriptions. Interventions to improve uptake should focus on increasing patient and provider awareness, reducing nirmatrelvir/ritonavir prescribing disparities, and ensuring treatment initiation within 5 days.