Therapeutic Drug Monitoring and Dosage Adjustments of Immunosuppressive Drugs When Combined With Nirmatrelvir/Ritonavir in Patients With COVID-19

IPNA clinical practice recommendations on care of pediatric patients with pre-existing kidney disease during seasonal outbreak of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic, instigated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has profoundly impacted healthcare infrastructures around the globe. While children are usually asymptomatic or have mild symptoms, children with pre-existing kidney conditions require specialized attention. This pivotal report, championed by the International Pediatric Nephrology Association (IPNA), delivers precise and actionable recommendations tailored for pediatric patients with kidney ailments in this pandemic landscape. Central to our findings are rigorous infection control protocols. These are particularly stringent in high-risk zones, emphasizing telehealth's indispensable role, the significance of curtailing in-person consultations, and the imperative of following rigorous guidelines in regions with heightened COVID-19 prevalence. Additionally, the report delves into vaccination approaches for children with kidney issues, highlighting that the choice of vaccine is often governed by regional accessibility and policy frameworks, rather than a universal preference. A notable observation is the potential correlation between COVID-19 vaccines and specific kidney disorders. However, establishing a direct causal link remains elusive. In summary, our research accentuates the critical need for specialized pediatric kidney care during global health crises and reaffirms the continuous research imperative, especially regarding vaccination ramifications.

Comparative Effectiveness of Outpatient COVID-19 Therapies in Solid Organ Transplant Recipients

BACKGROUND

Multiple outpatient therapies have been developed for COVID-19 in high-risk individuals, but solid organ transplant (SOT) recipients were not well represented in controlled clinical trials. To date, few comparative studies have evaluated outcomes between outpatient therapies in this population.

METHODS

We performed a retrospective cohort study using de-identified administrative claims data from OptumLabs Data Warehouse. Patients were included if they were age ≥ 18 years, diagnosed with COVID-19 between January 2022 and December 2023, and underwent SOT prior to COVID-19. The primary outcome was 30-day hospitalization. Stabilized inverse probability of treatment weighting was used to account for potential confounding variables.

RESULTS

4192 SOT recipients with COVID-19 were identified. 1403 received an outpatient COVID-19 therapy, including anti-spike monoclonal antibodies (N = 748, 53.3%), molnupiravir (N = 327, 23.3%), ritonavir-boosted nirmatrelvir (N = 217, 15.5%), or remdesivir (N = 141, 10.0%). In weighted analysis compared to no treatment, anti-spike monoclonal antibodies (hazard ratio [HR] 0.39, 95% confidence interval [CI] 0.28-0.55; p < 0.001), molnupiravir (HR 0.56, 95% CI 0.36-0.89; p = 0.013), and nirmatrelvir (HR 0.47, 95% CI 0.25-0.89; p = 0.020) were associated with reduced hospitalization risk, while remdesivir (HR 1.00, 95% CI 0.50-1.98; p = 0.992) was not. Hospitalization rates were similar between the treatment agents, apart from remdesivir showing a higher risk compared to anti-spike monoclonal antibodies.

CONCLUSIONS

Outpatient COVID-19 therapies were largely associated with improved outcomes among SOT recipients. These treatment agents showed similar rates of 30-day hospitalization, except for remdesivir. The choice of outpatient COVID-19 therapy in SOT recipients should primarily account for patients' individual circumstances and drug-drug interactions rather than differential therapeutic efficacy.

A patent review of CYP3A4 inhibitors (2018 - present)

INTRODUCTION

Cytochrome P450 3A4 (CYP3A4), one of the most important xenobiotic-metabolizing enzymes, plays a central role in drug metabolism and acts as a key mediator in drug-drug interactions. CYP3A4 inhibitors can potentiate the in vivo therapeutic effects of CYP3A4-substrate drugs via enhancing their systematic exposure levels. Two CYP3A4 inhibitors (ritonavir and cobicistat) have already been approved for modulating the exposure levels of CYP3A4-substrate drugs.

AREAS COVERED

This review summarizes the newly patented CYP3A4 inhibitors in the period (2018-2024) by using the keywords 'CYP3A4' and 'inhibitor' in Espacenet database from academic institutions and industrial companies. The chemical structures and inhibition profiles of the patented CYP3A4 inhibitors, including the anti-CYP3A4 potency, inhibitory mechanisms, and other relevant information, are summarized and discussed.

EXPERT OPINION

Although diverse CYP3A4 inhibitors have been developed in the past few years, the development of more efficacious CYP3A4 inhibitors with favorable pharmacokinetic and safety profiles is still challenging. To maximize the benefit of CYP3A4 inhibitors, combination strategies should be used for the development of highly specific CYP3A4 inhibitors or degraders with efficacious anti-CYP3A4 effects and favorable pharmacokinetic profiles. Meanwhile, more efforts should be made to address the organ-targeting or tumor-targeting ability of CYP3A4 inhibitors for specific purposes.

Pharmacokinetic Boosting of Calcineurin Inhibitors in Transplantation: Pros, Cons, and Perspectives

ABSTRACT

The concept of pharmacokinetic (PK) boosting of calcineurin inhibitors (CNI) emerged after the FDA approval of cyclosporine-A. Several studies followed, and the proof of concept was well established by the late 1990s. This also continued for the next blockbuster immunosuppressant, tacrolimus. The driver for such research was an endeavor to save costs, as both drugs were expensive due to patent protection. Two CYP inhibitors, ketoconazole and diltiazem, have been extensively studied in this context and continue to be prescribed off-label along with the CNI. It has been observed that using ketoconazole reduces the dose requirement of tacrolimus by about 50% and 30% with diltiazem, which is in conformity with their pharmacological actions. Off-label co-prescription of these drugs with CNI is often encountered in low and middle-income countries. The foremost reason cited is economic. This article collates the evidence from the clinical studies that evaluate the PK-boosting effects of CNI and also reviews the gaps in the current evidence base. The current knowledge prevents the transplant community from making meaningful inferences about the risks and benefits of such strategies. Although the PK-boosting strategy can lead to serious adverse events, emerging evidence suggests that it may be advantageous for individuals with high CNI dose requirements. Hence, PK boosting may be an unmet need in the therapeutics of CNI. Nevertheless, there are several unanswered questions surrounding such use, and therefore, this merits testing in well-designed clinical studies. Moreover, drugs with better safer profiles and a history of successful PK boosting may be considered for evaluation with CNI.

Lupus and SARS-CoV-2: What have we learned after the pandemic?

After the end of the COVID-19 public health emergency, we analysed the relationship between Systemic Lupus Erythematosous (SLE) and COVID-19 from the virologist's perspective based on recent findings. SLE and COVID-19 co-morbidity present unique challenges, as individuals with SLE may be at increased risk for severe COVID-19 illness due to immune system abnormalities and ongoing therapies. Effective management of both diseases requires careful monitoring, adherence to vaccination programs, preventive measures and approved and patient-tailored therapies. This review covers various aspects, including the clinical outcome of SLE patients infected by SARS-CoV-2, the impact of this infection on SLE onset or flare-ups and the benefits of vaccination for this population. Furthermore, this review presents the most recent recommendations on clinical management of COVID-19 in rheumatic patients, including those with SLE, discussing the currently available therapeutic options. Finally, we explore the most effective tools for SARS-CoV-2 diagnosis in autoimmune conditions and examine prognostic biomarkers in COVID-19 rheumatic patients with potential implications on their clinical oversight. By adopting a comprehensive approach, we address these complexities from the virologist's perspective, aiming to improve health care for this vulnerable population.

Should We Transplant Candidates With a Positive SARS-CoV-2 RT-PCR Test?

BACKGROUND

It remains unclear whether physicians should accept transplantation offers for candidates with a positive SARS-CoV-2 reverse transcription polymerase chain reaction test due to the potential risk of severe infection after initiating immunosuppressive therapy.

METHODS

A multicenter observational study was conducted in 19 French solid organ transplantation units. Patients on the waiting list for liver or kidney transplants who had a positive SARS-CoV-2 reverse transcription polymerase chain reaction nasopharyngeal swab at the time of transplantation were recorded.

RESULTS

Sixty-five patients were included. The recipients were predominantly men (n = 40; 62%) with a mean age of 55.4 y (SD = 16.5). On the day of transplantation, 2 patients exhibited symptoms compatible with COVID-19. The majority of patients (n = 55; 85%) underwent thoracic imaging, with only 3 patients showing imaging results compatible with COVID-19. Ten patients (28%) had a cycle threshold value <30. Anti-SARS-CoV-2 spike protein serology within 3 mo before transplantation was available for 36 patients; only 2 patients were seronegative. Due to COVID-19, physicians adapted the immunosuppressive therapy for 16 patients (25%). Specific antiviral therapy was used for 15 patients (23%), primarily remdesivir (n = 12). Overall, the majority of patients did not receive any adjustment of immunosuppressive therapy or antiviral treatment (n = 36; 55%). The outcomes were generally favorable even for patients with the lowest cycle threshold values, indicating a high viral load. Four patients died during follow-up, although none of these deaths were attributable to COVID-19.

CONCLUSIONS

Transplantation appears to be safe for patients who are asymptomatic or have mild symptoms, reassuring thoracic imaging, and a history of anti-SARS-CoV-2 infection and/or immunization.

The interaction between nirmatrelvir/ritonavir and sirolimus: a case report of a kidney recipient with renal insufficiency and COVID-19

Nirmatrelvir/ritonavir is a novel drug combination authorized by the US Food and Drug Administration for the treatment of coronavirus disease 2019 (COVID-19). This report describes the case of a patient with a prior history of kidney transplantation who received nirmatrelvir/ritonavir. In this case, sirolimus use was successfully stopped before nirmatrelvir/ritonavir treatment, and the nirmatrelvir/ritonavir trough concentration was determined. During nirmatrelvir/ritonavir treatment, the sirolimus trough concentration remained stable. This case highlights the risk associated with the concomitant administration of sirolimus and nirmatrelvir/ritonavir. Providers should therefore be cautious when prescribing nirmatrelvir/ritonavir to kidney transplant recipients currently receiving sirolimus, with caution exercised based on creatinine clearance.

Inappropriate Prescribing of Nirmatrelvir/Ritonavir in Solid Organ Transplantation With COVID-19 Infection: A Multicenter Retrospective Study

BACKGROUND

Nirmatrelvir-ritonavir (NR) has demonstrated effectiveness in halting the progression to severe coronavirus disease 2019 (COVID-19) among solid organ transplant recipients (SOTRs) infected with Severe Acute Respiratory Syndrome Coronavirus 2. However, it has a wide range of interactions, especially with immunosuppressants. The study aimed to comprehensively evaluate the Inappropriate prescribing of NR and immunosuppressants in SOTRs with COVID-19, while also highlighting the essential aspects.

METHODS

We included hospitalized SOTRs who received NR at five tertiary hospitals between December 2022 and June 2023, and evaluated their prescription.

RESULTS

A total of 211 patients were enrolled, of which 205 did not meet all criteria for appropriate prescribing (97.16%). Inappropriateness primarily stemmed from starting treatment more than 5 days after symptom onset (87.68%), followed by application in severe-to-critical cases of COVID-19 (52.13%), the inappropriate dosages based on renal function (47.87%). Contraindications encompassed 17.06% of patients with severe renal impairment and 5.69% with contraindicated drug interactions. Inappropriate resumption of immunosuppressants accounted for a larger proportion than inappropriate discontinuation or dose adjustment (30.16% vs 8.99%). More than one-third of patients neglected to monitor concentrations. About 8% experienced abnormal high concentrations.

CONCLUSION

Inappropriate prescribing of NR is widespread among hospitalized SOTRs. Adjusting doses based on patients' renal function and paying attention to concurrent use of immunosuppressive drugs are crucial, and therapeutic drug monitoring is necessary. Clinical practitioners should enhance their vigilance and attention.

Factors influencing Nirmatrelvir/Ritonavir concentration in patients with COVID-19

BACKGROUND

In the filed of antiviral therapy, effective therapeutic concentration is beneficial to shorten the recovery time of patients and reduce the transmission rate.The aim of this study is to retrospectively analyze the factors that lead to the drug concentration of Nirmatrelvir /Ritonavir (NMV/RTV) not reaching the standard.

METHODS

In this study, the NMV/RTV drug concentration(Cnmv/rtv) data (n = 114) of COVID-19 patients over 18 years old were collected from May 2022 to July 2022, and the results of the patients were retrospectively compared. According to the analysis of the early study of NMV/RTV, combined with the research results at home and abroad, according to whether the measured drug concentration > 987 ng/ml, the patients were divided into target group and non-target group,The non-target group was defined as not reaching the trough concentration level.

RESULTS

Serum NMV/RTV concentration in adult patients was correlated with prognostic nutritional index [PNI, (P < 0.05)], height (P < 0.05), weight (P < 0.05) and creatinine clearance [Crcl, (P < 0.05)]. Multivariate analysis showed that height, weight, PNI, lymphocyte (LYM) and CrCl were independent influencing factors of NMV/RTV trough concentration. However, after the correction of BMI calculation, there was no correlation between NMV/RTV and BMI, so in the clinical medication plan, the drug was not adjusted according to the height and weight.

CONCLUSIONS

The serum NMV/RTV concentration of adult patients gradually decreased with the increase of CrCl. For patients with high and low CrCl, the trough concentration of NMV/RTV should be continuously monitored and the dosing regimen should be adjusted to achieve the target trough concentration in these patients to reduce the effect of CrCl. PNI is also a key factor affecting drug concentration. For poor nutritional status, drug concentration should be closely monitored and the dose should be adjusted.

Supply of nirmatrelvir/ritonavir and molnupiravir for patients with COVID-19 in the first eight months since listing on the Australian Pharmaceutical Benefits Scheme: A retrospective observational study

OBJECTIVES

To compare the supply of molnupiravir and nirmatrelvir/ritonavir in relation to patient characteristics and other co-prescribed medicines and to estimate the number of patients without contraindications to nirmatrelvir/ritonavir who were treated with molnupiravir.

STUDY DESIGN, SETTING

Retrospective observational study of patients identified in the Pharmaceutical Benefits Scheme (PBS) 10 % sample dataset who were supplied with either molnupiravir or nirmatrelvir/ritonavir between May and December 2022. We supplemented the PBS dataset with aggregated counts from published literature to determine prevalence of clinical contraindications to nirmatrelvir/ritonavir.

MAIN OUTCOME MEASURES

We used multivariable Poisson regression to estimate risk ratios (RR) of receiving nirmatrelvir/ritonavir over molnupiravir.

RESULTS

We identified 54,550 patients who received either nirmatrelvir/ritonavir (26.8 %) or molnupiravir (73.2 %). Their average age was 71.6 (SD = 13.4) years and 57.1 % were female. Patients were less likely to receive nirmatrelvir/ritonavir with increasing age (RR = 0.50; 95 % CI: 0.48-0.53; for ages 85 + compared to < 65 years) or who had received medicines contraindicated for use with nirmatrelvir/ritonavir (RR = 0.66; 95 % CI: 0.64-0.68). During the study period, we estimated that between 28.4 % and 45.4 % of patients aged ≥ 65 years had received molnupiravir in the absence of pharmacological and clinical contraindications to nirmatrelvir/ritonavir.

CONCLUSION

Many prescriptions were written for molnupiravir where there were no contraindications to nirmatrelvir/ritonavir. The benefits that followed from prompt government action in approving and obtaining nirmatrelvir/ritonavir were therefore likely to be less than they could potentially have been. Governments should consider investing in quality improvement systems to ensure the best outcomes in terms of efficacy and safety.

Effect of rifampicin administration on CYP induction in a dermatomyositis patient with vasospastic angina attributable to nilmatrelvir/ritonavir-induced blood tacrolimus elevation: A case report

Ritonavir (RTV), which is used in combination with nilmatrelvir (NMV) to treat coronavirus disease 2019 (COVID-19), inhibits cytochrome P450 (CYP) 3A, thereby increasing blood tacrolimus (TAC) levels through a drug-drug interaction (DDI). We experienced a case in which a DDI between the two drugs led to markedly increased blood TAC levels, resulting in vasospastic angina (VSA) and acute kidney injury (AKI). Rifampicin (RFP) was administered to induce CYP3A and promote TAC metabolism. A 60-year-old man with dermatomyositis who was taking 3 mg/day TAC contracted COVID-19. The patient started oral NMV/RTV therapy, and he was admitted to the hospital after 4 days because of chest pain and AKI. On day 5, his blood TAC level increased markedly to 119.8 ng/mL. RFP 600 mg was administered once daily for 3 days, and his blood TAC level decreased to the therapeutic range of 9.6 ng/mL on day 9, leading to AKI improvement. Transient complete atrioventricular block and nonsustained ventricular tachycardia were present during chest pain. In the coronary spasm provocation test, complete occlusion was observed in the right coronary artery, leading to a diagnosis of VSA. VSA and AKI are possible side effects of high blood TAC levels caused by DDI, and attention should be paid to cardiovascular side effects such as VSA and AKI associated with increased blood levels of TAC when it is used together with NMV/RTV. When blood levels of TAC increase, oral RFP can rapidly decrease TAC blood levels and potentially reduce its toxicity.

A Perspective on Evaluating Life Stage Differences in Drug Dosages for Drug Labeling and Instructions

Drug labeling and instructions provide essential information for patients regarding the usage of drugs. Instructions for the dosage of drug usage are critical for the effectiveness of the drug and the safety of patients. The dosage of many drugs varies depending on the patient's age. However, as our understanding of human biology deepens, we believe that these instructions need to be modified to incorporate different life stages. This is because human biology and metabolism differ significantly among different life stages, and their responses to drugs also vary. Additionally, the same age of different persons may fall into different life stages. Therefore, our group from multiple institutes and countries proposes a reexamination of whether incorporating life stages in all or any drug instructions will greatly enhance drug efficiency and patients' health.

Population pharmacokinetics of nirmatrelvir in Chinese patients with COVID-19: Therapeutic drug monitoring and dosing regimen selection in clinical practice

OBJECTIVES

To establish a population pharmacokinetics (PopPK) model of nirmatrelvir in Chinese COVID-19 patients and provide reference for refining the dosing strategy of nirmatrelvir in patients confirmed to be infected with SARS-CoV-2.

METHODS

A total of 80 blood samples were obtained from 35 mild to moderate COVID-19 patients who were orally administered nirmatrelvir/ritonavir tablets. The PopPK model of nirmatrelvir was developed using a nonlinear mixed effects modelling approach. The stability and prediction of the final model were assessed through a combination of goodness-of-fit and bootstrap method. The exposure of nirmatrelvir across various clinical scenarios was simulated using Monte Carlo simulations.

RESULTS

The pharmacokinetics of nirmatrelvir was well characterised by a one-compartment model with first-order absorption, and with creatinine clearance (Ccr) as the significant covariate. Typical population parameter estimates of apparent clearance and distribution volume for a patient with a Ccr of 95.5 mL·min-1were 3.45 L·h-1 and 48.71 L, respectively. The bootstrap and visual predictive check procedures demonstrated satisfactory predictive performance and robustness of the final model.

CONCLUSION

The final model was capable of offering an early prediction of drug concentration ranges for different nirmatrelvir dosing regimens and optimise the dose regimen of nirmatrelvir in individuals with confirmed SARS-CoV-2 infection.

Pharmacokinetics of nirmatrelvir/ritonavir and the drug-drug interaction with calcineurin inhibitor in renal transplant recipients

OBJECTIVES

To describe the pharmacokinetic (PK) characteristics of nirmatrelvir/ritonavir in renal transplant recipients and explore the potential factors that related to the PK variance of nirmatrelvir/ritonavir and its interaction with calcineurin inhibitor (CNI).

METHODS

Renal transplant recipients treated with CNI and nirmatrelvir/ritonavir were prospectively enrolled. Steady-state plasma concentrations of nirmatrelvir/ritonavir were determined by high-performance liquid chromatography-tandem mass spectrometry, and the PK parameters were calculated using non-compartmental analysis. Spearman correlation analysis was used for exploring influencing factors.

RESULTS

A total of eight recipients were enrolled; for nirmatrelvir and ritonavir, AUC/dose was 0.24179 ± 0.14495 and 0.06196 ± 0.03767 μg·h·mL-1·mg-1. Red blood cell (RBC), hematocrit (Ht), hemoglobins (Hb), and creatinine clearance (Ccr) were negatively correlated with AUC/dose of nirmatrelvir, while Ccr, CYP3A5 genotype, and CYP3A4 genotype were related to the AUC/dose of ritonavir. Ccr was negatively correlated with the C0/dose of tacrolimus (TAC) after termination of nirmatrelvir/ritonavir (rs =  -0.943, p = 0.008).

CONCLUSIONS

The PK characteristics of nirmatrelvir/ritonavir vary greatly among renal transplant recipients. Factors including Ccr and CYP3A5 genotype were related to the in vivo exposure of nirmatrelvir/ritonavir. During the whole process before and after nirmatrelvir/ritonavir therapy, it is recommended to adjust the CNI basing on renal function to avoid CNI toxicity exposure.

A biological pharmacology network to secure the risk of drug-drug interaction with nirmatrelvir/ritonavir

Nirmatrelvir/ritonavir is a protease inhibitor antiviral drug indicated in the treatment of severe acute respiratory syndrome coronavirus-2 infections in high-risk patients for a severe disease. Unfortunately, ritonavir, used to boost nirmatrelvir pharmacokinetics, can also inhibit or induce the metabolism of other co-administered drugs substrates. This may lead to a subsequent risk of adverse drug reaction and lack of efficacy. In this study, we aimed at describing the expert advices provided by the biological pharmacology network of the SFPT (i.e., the therapeutic drug monitoring specialists working in the laboratories of the pharmacology departments in France/Belgium). From February to August 2022, we collected all specialized advices provided by the biological pharmacology network of the SFPT. Seven pharmacology departments actively participated in the study (Brussels Saint-Luc Hospital in Belgium, Caen, Dijon, Nantes, Nancy, Rennes and Toulouse in France). We collected the following data: patient's age, date of nirmatrelvir/ritonavir initiation, clinical department requiring the expert advice, patient's treatments, and advice provided. One hundred and six expert advice on 753 drugs were provided during the seven months of data collection. Two centers provided 83% of all the expert advice (around 8/month). Patients originated form a transplantation department in 65% of the cases. The most common request were for cardiac drugs (28%), immunosuppressive drugs (24%) and endocrine drugs (18%). The advice were distributed as follows: treatment continuation, treatment discontinuation during the antiviral course, dosage adjustment, and treatment switch in 59%, 28%, 11%, and 1.6% of the cases, respectively. Only 2 pieces of advice (0.3%) constituted treatment contra-indications. Drug monitoring was proposed in 10% of prescription lines. Expert advice provided by the biological pharmacology network of the SFPT allows securing the combination of nirmatrelvir/ritonavir with other concomitant drugs. Most of eligible patients to the antiviral drug can benefit from it despite the risk of drug-drug interaction.

Influence of ensitrelvir or nirmatrelvir/ritonavir on tacrolimus clearance in kidney transplant recipients: a single-center case series

BACKGROUND

Among the oral antivirals used for treating patients with mild-to-moderate novel coronavirus disease 2019 (COVID-19), nirmatrelvir/ritonavir (NMV/RTV) and ensitrelvir (ESV) are inhibitors of cytochrome P450 (CYP) 3A, and therefore, can cause drug-drug interactions with concomitant medications. Tacrolimus (TAC), a substrate of CYP3A4/5, is administered for a long period to prevent rejection after kidney transplantation. TAC should be discontinued while using NMV/RTV because blood TAC levels significantly increase when these drugs are concomitantly administered. However, the influence of ESV on blood TAC levels has not yet been reported, and the management of TAC doses during the use of ESV remains unclear.

CASE PRESENTATION

We experienced three kidney transplant recipients with COVID-19, whose blood trough levels of TAC increased by the concomitant use of NMV/RTV or ESV. In two patients administering NMV/RTV, blood trough levels of TAC increased more than tenfold after combination therapy, whereas in one patient administering ESV, TAC level increased approximately threefold.

CONCLUSIONS

These cases suggest that TAC administration should be discontinued during NMV/RTV treatment to maintain blood TAC levels within the therapeutic range, and a reduced TAC dose is sufficient during ESV treatment.

Ritonavir: 25 Years' Experience of Concomitant Medication Management. A Narrative Review

Ritonavir is a potent inhibitor of the cytochrome P450 3A4 enzyme and is commonly used as a pharmacokinetic (PK) enhancer in antiviral therapies because it increases bioavailability of concomitantly administered antivirals. Decades of experience with ritonavir-enhanced HIV therapies and, more recently, COVID-19 therapies demonstrate that boosting doses of ritonavir are well tolerated, with an established safety profile. The mechanisms of PK enhancement by ritonavir result in the potential for drug-drug interactions (DDIs) with several classes of drugs, thus making co-medication management an important consideration with enhanced antiviral therapies. However, rates of DDIs with contraindicated medications are low, suggesting these risks are manageable by infectious disease specialists who have experience with the use of PK enhancers. In this review, we provide an overview of ritonavir's mechanisms of action and describe approaches and resources available to mitigate adverse events and manage concomitant medication in both chronic and short-term settings.

Case report: Paralytic ileus resulted from nirmatrelvir/ritonavir-tacrolimus drug-drug interaction in a systemic lupus erythematosus patient with COVID-19

Patients with systemic autoimmune rheumatic diseases are at a high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and effective antiviral treatments including nirmatrelvir/ritonavir can improve their outcomes. However, there might be potential drug-drug interactions when these patients take nirmatrelvir/ritonavir together with immunosuppressants with a narrow therapeutic window, such as tacrolimus and cyclosporine. We present a case of paralytic ileus resulting from tacrolimus toxicity mediated by the use of nirmatrelvir/ritonavir in a patient with systemic lupus erythematosus (SLE). A 37-year-old female SLE patient was prescribed nirmatrelvir/ritonavir without discontinuing tacrolimus. She presented to the emergency room with symptoms of paralytic ileus including persistent abdominal pain, nausea, and vomiting, which were verified to be associated with tacrolimus toxicity. The blood concentration of tacrolimus was measured >30 ng/mL. Urgent medical intervention was initiated, while tacrolimus was withheld. The residual concentration was brought within the appropriate range and tacrolimus was resumed 8 days later. Physicians must be aware of the potential DDIs when prescribing nirmatrelvir/ritonavir, especially to those taking immunosuppresants like tacrolimus.

Adaptative Strategy of Immunosuppressive Drugs Dosage Adjustments When Combined With Nirmatrelvir/Ritonavir in Solid Organ Transplant Recipients With COVID-19

Nirmatrelvir/ritonavir is a promising option for preventing severe COVID-19 in solid organ transplant recipients with SARS-CoV-2 infection. However, concerns have arisen regarding potential drug interactions with calcineurin inhibitors (CNI). This two-phase multicentre retrospective study, involving 113 patients on tacrolimus and 13 on cyclosporine A, aimed to assess the feasibility and outcomes of recommendations issued by The French societies of transplantation (SFT) and pharmacology (SFPT) for CNI management in this context. The study first evaluated adherence to recommendations, CNI exposure, and clinical outcomes. Notably, 96.5% of patients on tacrolimus adhered to the recommendations, maintaining stable tacrolimus trough concentrations (C0) during nirmatrelvir/ritonavir treatment. After reintroduction, most patients experienced increased C0, with 42.9% surpassing 15 ng/mL, including three patients exceeding 40 ng/mL. Similar trends were observed in cyclosporine A patients, with no COVID-19-related hospitalizations. Moreover, data from 22 patients were used to refine the reintroduction strategy. Modelling analyses suggested reintroducing tacrolimus at 50% of the initial dose on day 8, and then at 100% from day 9 as the optimal approach. In conclusion, the current strategy effectively maintains consistent tacrolimus exposure during nirmatrelvir/ritonavir treatment, and a stepwise reintroduction of tacrolimus may be better suited to the low CYP3A recovery.

A Case Report of Drug Interactions Between Nirmatrelvir/Ritonavir and Tacrolimus in a Patient With Systemic Lupus Erythematosus

Nirmatrelvir/ritonavir is a treatment for COVID-19 consisting of nirmatrelvir, which has anti-SARS-CoV-2 activity, and ritonavir, a booster to maintain blood levels. Ritonavir is known to be a potent inhibitor of cytochrome P450 3A (CYP3A), and interactions with CYP3A-metabolized drugs, such as the immunosuppressant tacrolimus, can be problematic. Ritonavir's inhibition of CYP3A is irreversible due to covalent binding, and its inhibitory effects are expected to persist until replaced by new CYP3A. Here, we report a case where the combination of nirmatrelvir/ritonavir and tacrolimus resulted in toxic tacrolimus blood levels. A patient on tacrolimus for systemic lupus erythematosus (SLE) developed COVID-19 and was prescribed nirmatrelvir/ritonavir. After starting the combination of nirmatrelvir/ritonavir and tacrolimus, the patient's tacrolimus blood levels became abnormally high, leading to the discontinuation of these drugs due to symptoms of tacrolimus toxicity. Even after ritonavir blood levels had fallen below the detection limit, the decline in tacrolimus blood levels was delayed. The CYP3A inhibition of ritonavir persists even when its blood concentration decreases, emphasizing the need for careful consideration of concomitant medications before starting nirmatrelvir/ritonavir therapy. Adjustments or discontinuation may be necessary.

Nirmatrelvir/ritonavir-induced elevation of blood tacrolimus levels in a patient in the maintenance phase post liver transplantation

Nirmatrelvir is an orally administered anti-SARS-CoV-2 drug used in combination with ritonavir, the drug-metabolizing cytochrome P450 (CYP) 3A inhibitor, to evade metabolism and extend bioavailability. Meanwhile, the immunosuppressant tacrolimus is a CYP3A4/5 substrate, and CYP3A inhibition results in drug-drug interactions. Herein, we report the case of a coronavirus disease 19 (COVID-19) patient in the maintenance phase post liver transplantation, receiving tacrolimus treatment, with a marked increase of blood tacrolimus levels after the initiation of concomitant nirmatrelvir/ritonavir treatment. A 61-year-old Japanese woman underwent a living donor liver transplant for Caroli disease 25 years ago and received tacrolimus 2 mg/day for immunosuppressive treatment. Three days before the observed high tacrolimus blood concentration, she presented to our emergency department with a fever and was diagnosed with COVID-19. She was prescribed an adjusted dose of nirmatrelvir/ritonavir (150 mg/100 mg, twice daily) for 5 days as a high-risk case with immunosuppressive treatment and reduced renal function (estimated glomerular filtration rate, eGFR: 46.6 mL/min/1.73 m2). At the return visit on day 1, blood tacrolimus level was >60 ng/mL on trough sampling, above the upper limit of measurement, with nausea and vomiting as side effects. Tacrolimus treatment was discontinued on the same day. Drug-drug interactions resulting from CYP3A inhibition by nirmatrelvir/ritonavir were deemed responsible for elevated blood tacrolimus levels. Therefore, in liver transplant recipients, tacrolimus dose reduction or discontinuation is required during COVID-19 treatment with nirmatrelvir/ritonavir.

Evaluation of the efficacy and safety of nirmatrelvir/ritonavir co-administration inpatients with rheumatic disease infected with SARS-CoV-2: a real-world study

Background: The breakthrough development of novel severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccines and oral antivirals have played a critical role in curtailing the spread of the pandemic and dramatically reducing the morbidity and mortality rates among those infected. Among these oral antivirals, nirmatrelvir/ritonavir (NR) has been repurposed successfully for use against coronavirus disease-2019 (COVID-19) and is now readily available on the market with promising therapeutic effects. The availability of convenient and effective NR treatments for COVID-19 greatly mitigates the severity of the epidemic and contributes to an early end to the pandemic. Furthermore, certain patient subgroups, specifically those with rheumatic disease (RD) who are currently undergoing intensive immunodeficiency and/or immunosuppressive treatments, continue to be vulnerable and at a higher risk of experiencing severe consequences from COVID-19. Additionally, it has also been observed that NR exhibited prevalent drug-drug interactions of clinical significance, and more instances of COVID-19 rebound were being recognized with increasing frequency. Methods: A retrospective cohort study was conducted on a real-world RD population who were infected with SARS-CoV-2 and treated with NR. The time of symptom resolution, length of hospitalization, and response rate were assessed. Results were compared among the standard regimen and non-standard regimen groups, early NR regimen and late NR regimen groups, and the NR indication regimen and NR non-indication regimen groups. During the course, all grades of adverse drug reactions (ADRs) directly associated with NR administration and associated with drug-drug interactions (DDIs) were also monitored. Results: A total of 32 patients with RD, who were infected with SARS-CoV-2 and received NR, were retrospectively identified and divided into different groups. We found that the standard regimen group and the early NR regimen group had a shorter median time of symptom resolution compared to the control group [9.0 (interquartile range [IQR], 8.3-11.3) vs. 21.5 (IQR16.0-24.0) days, p < 0.001 and 9.0 (IQR 8.3-11.3) vs. 23.0 (IQR 18.0-24.0) days, p = 0.0]. We further found that even if the NR administration time exceeds 5 days, patients with RD who receive the NR indication regimen can still derive certain benefits from it. The proportion of patients who showed symptom improvement was higher in the NR indication regimen compared to the NR non-indication regimen group (n = 13/17 vs. 3/6, 76.5% vs. 50.0%) at the end of follow-up, and there was a statistical difference (p = 0.0) in the response rate of patients between the two groups. We also analyzed the effect of comorbidities on patient response rates and found that the percentage of patients who showed symptom improvement was higher in the group with <4 comorbidities compared to the group with ≥ 4 comorbidities (n = 7/7 vs. 16/25, 100.0% vs. 64.0%) at the end of follow-up. During the course, all grades of ADRs and grade ≥3ADRs directly associated with NR administration were not observed in any of the 32 cases. Despite discontinuing warfarin prior to NR application (using NR immediately on the first day of warfarin withdrawal), one patient still experienced an increased international normalized ratio [INR, 5.32(0.90-1.20)] and coagulation disorders (weak positive fecal occult blood test) on the second day after using NR. The INR levels decreased to nearly normal values, and coagulation disorders returned to normal after 2 days of discontinuing NR (the seventh day after the initial administration of NR). Conclusion: We showed NR therapy to be associated with a favorable outcome and an acceptable safety profile in an immunosuppressed population with RD during the Omicron surge. Early use of NR (within 5 days of symptom onset) could improve the prognosis of patients. NR administration for symptoms and confirmed SARS-CoV-2 infection after >5 days may also mitigate progression to severe disease and is a viable strategy. Our results highlight the importance of early utilization and/or NR indication, which may yield clinical advantages for patients with RD infected with SARS-CoV-2.

A model-based pharmacokinetic assessment of drug-drug interaction between tacrolimus and nirmatrelvir/ritonavir in a kidney transplant patient with COVID-19

We experienced a patient with a remarkable and prolonged increase in tacrolimus blood concentrations when nirmatrelvir/ritonavir was concomitantly used. The inhibitory intensity and duration of nirmatrelvir/ritonavir on tacrolimus pharmacokinetics were examined using a model-based analysis. A renal transplant patient taking oral tacrolimus continuously was treated with nirmatrelvir/ritonavir for 5 days. The baseline tacrolimus trough blood concentration was 4.2 ng/mL. Tacrolimus was discontinued on Day 6 after the concomitant administration of nirmatrelvir/ritonavir, and the trough concentration increased to 96.4 ng/mL on Day 7. The model-based analysis showed that tacrolimus clearance decreased to 35% and bioavailability increased by 18.7-fold after the coadministration of nirmatrelvir/ritonavir, compared with before the coadministration. Therefore, nirmatrelvir/ritonavir drastically decreased both the apparent clearance and apparent volume of distribution. Simulated tacrolimus concentrations could be best fitted to the observed concentrations when the inhibitory effects of nirmatrelvir/ritonavir were modeled to disappear over about 10 days by first-order elimination. In conclusion, nirmatrelvir/ritonavir greatly increases tacrolimus concentrations by not only reducing clearance, but also increasing bioavailability. Interactions between nirmatrelvir/ritonavir and low-bioavailability drugs which are substrates for CYP3A and P-glycoprotein, such as tacrolimus, are harmful, and concomitant use of these medicines should be avoided.

Design, synthesis and biological evaluation of chalcone derivatives as potent and orally active hCYP3A4 inhibitors

Human cytochrome P450 3A4 (hCYP3A4), one of the most important drug-metabolizing enzymes, catalyze the metabolic clearance of ∼50% therapeutic drugs. CYP3A4 inhibitors have been used for improving the in vivo efficacy of hCYP3A4-substrate drugs. However, most of existing hCYP3A4 inhibitors may trigger serious adverse effects or undesirable effects on endogenous metabolism. This study aimed to discover potent and orally active hCYP3A4 inhibitors from chalcone derivatives and to test their anti-hCYP3A4 effects both in vitro and in vivo. Following three rounds of screening and structural optimization, the isoquinoline chalcones were found with excellently anti-hCYP3A4 effects. SAR studies showed that introducing an isoquinoline ring on the A-ring significantly enhanced anti-CYP3A4 effect, generating A10 (IC50 = 102.10 nM) as a promising lead compound. The 2nd round of SAR studies showed that introducing a substituent group at the para position of the carbonyl group on B-ring strongly improved the anti-CYP3A4 effect. As a result, C6 was identified as the most potent hCYP3A4 inhibitor (IC50 = 43.93 nM) in human liver microsomes (HLMs). C6 also displayed potent anti-hCYP3A4 effect in living cells (IC50 = 153.00 nM), which was superior to the positive inhibitor ketoconazole (IC50 = 251.00 nM). Mechanistic studies revealed that C6 could potently inhibit CYP3A4-catalyzed N-ethyl-1,8-naphthalimide (NEN) hydroxylation in a competitive manner (Ki = 30.00 nM). Moreover, C6 exhibited suitable metabolic stability in HLMs and showed good safety profiles in mice. In vivo tests demonstrated that C6 (100 mg/kg, orally administration) significantly increased the AUC(0-inf) of midazolam by 3.63-fold, and strongly prolonged its half-life by 1.66-fold compared with the vehicle group in mice. Collectively, our findings revealed the SARs of chalcone derivatives as hCYP3A4 inhibitors and offered several potent chalcone-type hCYP3A4 inhibitors, while C6 could serve as a good lead compound for developing novel, orally active CYP3A4 inhibitors with improved druglikeness properties.

Tacrolimus-why pharmacokinetics matter in the clinic

The calcineurin inhibitor (CNI) Tacrolimus (Tac) is the most prescribed immunosuppressant drug after solid organ transplantation. After renal transplantation (RTx) approximately 95% of recipients are discharged with a Tac-based immunosuppressive regime. Despite the high immunosuppressive efficacy, its adverse effects, narrow therapeutic window and high intra- and interpatient variability (IPV) in pharmacokinetics require therapeutic drug monitoring (TDM), which makes treatment with Tac a major challenge for physicians. The C/D ratio (full blood trough level normalized by daily dose) is able to classify patients receiving Tac into two major metabolism groups, which were significantly associated with the clinical outcomes of patients after renal or liver transplantation. Therefore, the C/D ratio is a simple but effective tool to identify patients at risk of an unfavorable outcome. This review highlights the challenges of Tac-based immunosuppressive therapy faced by transplant physicians in their daily routine, the underlying causes and pharmacokinetics (including genetics, interactions, and differences between available Tac formulations), and the latest data on potential solutions to optimize treatment of high-risk patients.

Monitoring tacrolimus toxicity following Paxlovid administration in a liver transplant patient

Maintaining therapeutic plasma tacrolimus concentrations is essential for mitigating potential solid organ transplant rejection and preventing toxic adverse side effects. While patients can benefit greatly from tacrolimus therapy, co-administration of drugs such as Paxlovid (nirmatrelvir/ritonavir) place patients at serious risk for drug interactions and harm. Here we present a case of tacrolimus toxicity following Paxlovid administration in a liver transplant patient. Therapeutic drug monitoring was further complicated by a limited upper reportable threshold for tacrolimus testing and highlights the value of validating a higher limit to the clinical reportable range to improve tacrolimus monitoring and meet clinical needs in the setting of drug toxicity.

Is Azvudine Comparable to Nirmatrelvir-Ritonavir in Real-World Efficacy and Safety for Hospitalized Patients with COVID-19? A Retrospective Cohort Study

INTRODUCTION

Azvudine and nirmatrelvir-ritonavir are more extensively used to treat COVID-19 in China due to their earlier approval by the National Medical Products Administration. However, there has been a scarcity of research directly comparing the clinical outcomes between azvudine and nirmatrelvir-ritonavir till now. We aimed to make a head-to-head comparison of the efficacy and safety of azvudine or nirmatrelvir-ritonavir in hospitalized patients with COVID-19 in China.

METHODS

This retrospective cohort study was conducted using data collected from Tongde Hospital of Zhejiang Province between December 2022 and January 2023. All-cause mortality, risk of progressing to a critical condition, proportion with nucleic-acid negative conversion (PNANC), time to first nucleic-acid negative conversion (TFNANC), length of hospital stay and incidence of adverse events were systematically assessed as outcomes. Multi-model regression analysis, propensity-score-matching analysis, subgroup analysis and several sensitivity analyses were applied to compare these outcomes.

RESULTS

This study included a total of 1571 hospitalized patients with COVID-19, among whom 272 received nirmatrelvir-ritonavir and 156 received azvudine. We found no significant differences in all-cause mortality (HR 1.41; 95% CI 0.56-3.56; P = 0.471), risk of progressing to critical COVID-19 (HR 1.67; 95% CI 0.78-3.60; P = 0.189), PNANC (HR 0.87; 95% CI 0.69-1.09; P = 0.220), length of stay (β - 0.82; 95% CI - 2.78 to 1.15; P = 0.414) and adverse event rate (3.21% vs. 4.41%, P = 0.538) between the two groups, although azvudine was slightly less effective than nirmatrelvir-ritonavir. Meanwhile, the azvudine group exhibited a significantly longer TFNANC (β 2.53; 95% CI 0.76-4.29; P = 0.005) than the nirmatrelvir-ritonavir group. Results were similar for propensity-score matching and multiple sensitivity analyses.

CONCLUSION

Azvudine probably possessed comparable efficacy and safety to nirmatrelvir-ritonavir, although it was less effective than nirmatrelvir-ritonavir for some outcomes.

Multidisciplinary recommendations for the management of CAR-T recipients in the post-COVID-19 pandemic era

The outbreak of coronavirus disease 2019 (COVID-19) posed an unprecedented challenge on public health systems. Despite the measures put in place to contain it, COVID-19 is likely to continue experiencing sporadic outbreaks for some time, and individuals will remain susceptible to recurrent infections. Chimeric antigen receptor (CAR)-T recipients are characterized by durable B-cell aplasia, hypogammaglobulinemia and loss of T-cell diversity, which lead to an increased proportion of severe/critical cases and a high mortality rate after COVID-19 infection. Thus, treatment decisions have become much more complex and require greater caution when considering CAR T-cell immunotherapy. Hence, we reviewed the current understanding of COVID-19 and reported clinical experience in the management of COVID-19 and CAR-T therapy. After a panel discussion, we proposed a rational procedure pertaining to CAR-T recipients with the aim of maximizing the benefit of CAR-T therapy in the post COVID-19 pandemic era.

Real-World Evidence of the Top 100 Prescribed Drugs in the USA and Their Potential for Drug Interactions with Nirmatrelvir; Ritonavir

Nirmatrelvir (coadministered with ritonavir as PAXLOVIDTM) reduces the risk of COVID-19-related hospitalizations and all-cause death in individuals with mild-to-moderate COVID-19 at high risk of progression to severe disease. Ritonavir is coadministered as a pharmacokinetic enhancer. However, ritonavir may cause drug-drug interactions (DDIs) due to its interactions with various drug-metabolizing enzymes and transporters, including cytochrome P450 (CYP) 3A, CYP2D6, and P-glycoprotein transporters. To better understand the extent of DDIs (or lack thereof) of nirmatrelvir; ritonavir in a clinical setting, this study used real-world evidence (RWE) from the Optum Clinformatics Data Mart database to identify the top 100 drugs most commonly prescribed to US patients at high risk of progression to severe COVID-19 disease. The top 100 drugs were identified based on total counts associated with drugs prescribed to high-risk patients (i.e.,  ≥ 1 medical condition associated with an increased risk of severe COVID-19) who were continuously enrolled in the database throughout 2019 and had  ≥ 1 prescription claim. Each of the 100 drugs was then assessed for DDI risk based on their metabolism, excretion, and transport pathways identified from available US prescribing and medical literature sources. Seventy drugs identified were not expected to have DDIs with nirmatrelvir; ritonavir, including many cardiovascular agents, anti-infectives, antidiabetic agents, and antidepressants. Conversely, 30 drugs, including corticosteroids, narcotic analgesics, anticoagulants, statins, and sedatives/hypnotics, were expected to cause DDIs with nirmatrelvir; ritonavir. This RWE analysis is complementary to the prescribing information and other DDI management tools for guiding healthcare providers in managing DDIs.

Your Outpatient has Coronavirus Disease 2019: What Are the Treatment Options in the Current Severe Acute Respiratory Syndrome Coronavirus 2 Variant Climate?

Mutations accumulated by novel Severe Acute Respiratory Syndrome Coronavirus 2 Omicron sublineages contribute to evasion of previously effective monoclonal antibodies for treatment or prevention of Coronavirus Disease 2019 (COVID-19). Other authorized or approved antiviral drugs such as nirmatrelvir/ritonavir, remdesivir, and molnupiravir are, however, predicted to maintain activity against these sublineages and are key tools to reduce severe COVID-19 outcomes in vulnerable populations. A stepwise approach may be taken to target the appropriate antiviral drug to the appropriate patient, beginning with identifying whether a patient is at high risk for hospitalization or other complications of COVID-19. Among higher risk individuals, patient profile (including factors such as age, organ function, and comedications) and antiviral drug access inform suitable antiviral drug selection. When applied in targeted fashion, these therapies serve as a complement to vital ongoing nonpharmaceutical interventions and vaccination strategies that reduce morbidity and maximize protection against COVID-19.

Drug-drug interaction of Nirmatrelvir/ritonavir and tacrolimus: A potential risk disproportionality analysis of nephrotoxicity from COVID-19 reports in FAERS

BACKGROUND

Nirmatrelvir/ritonavir is a new oral antiviral agent for COVID-19, and tacrolimus is a widely used immunosuppressant. Drug-drug interaction between Nirmatrelvir/ritonavir and tacrolimus is expected. However, information regarding the drug-drug interaction in a real-world setting is limited. We aim to evaluate drug-drug interaction between tacrolimus and Nirmatrelvir/ritonavir and perform a disproportionality analysis to assess the potential risk of nephrotoxicity due to their combination for COVID-19 treatment based on the FAERS database.

RESEARCH DESIGN AND METHODS

Disproportionality analysis was performed using the reporting odds ratio (ROR) method, and subset analysis was conducted based on the background of COVID-19 drugs combined with tacrolimus more than 10 times.

RESULTS

In disproportionality analysis, combination of Nirmatrelvir/ritonavir and tacrolimus was significantly associated with acute kidney injury (41.13%), serum creatinine increased (14.18%), renal failure (2.84%), and renal impairment (2.84%). These positive signals of acute kidney injury and serum creatinine increased still strongly retained in subset analysis. No similar positive signals were detected in Nirmatrelvir/ritonavir-single group. Only in Cilgavimab/Tixagevimab-tacrolimus group and Remdesivir-tacrolimus group, acute kidney injury was recognized as weakly positive signals and disappeared in subset analysis.

CONCLUSIONS

The study results show significant drug-drug interaction between Nirmatrelvir/ritonavir and tacrolimus and confirm that their combination for COVID-19 treatment greatly increases risk of acute kidney injury.

Acute graft-versus-host disease

Acute graft-versus-host disease (GVHD) is a common immune complication that can occur after allogeneic haematopoietic cell transplantation (alloHCT). Acute GVHD is a major health problem in these patients, and is associated with high morbidity and mortality. Acute GVHD is caused by the recognition and the destruction of the recipient tissues and organs by the donor immune effector cells. This condition usually occurs within the first 3 months after alloHCT, but later onset is possible. Targeted organs include the skin, the lower and upper gastrointestinal tract and the liver. Diagnosis is mainly based on clinical examination, and complementary examinations are performed to exclude differential diagnoses. Preventive treatment for acute GVHD is administered to all patients who receive alloHCT, although it is not always effective. Steroids are used for first-line treatment, and the Janus kinase 2 (JAK2) inhibitor ruxolitinib is second-line treatment. No validated treatments are available for acute GVHD that is refractory to steroids and ruxolitinib, and therefore it remains an unmet medical need.

Clinical efficacy analysis of paxlovid in children with hematological diseases infected with the omicron SARS-CoV-2 new variant

Objective

To summarize the clinical characteristics of children with hematological malignancies co-infected with novel coronavirus and explore the safety and effectiveness of Paxlovid treatment.

Methods

From December 10, 2022, to January 20, 2023, the clinical data of children with hematological diseases diagnosed with novel coronavirus infection in the outpatient and emergency department of the Seventh Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed.

Results

According to whether to give paxlovid or not, it is divided into group A (paxlovid group) and group B (non-paxlovid group). The length of fever was 1-6 days in group A and 0-3 days in group B. The viral clearance time was shorter in group A than in group B. The inflammatory indexes CRP and PCT were significantly higher in group A than in group B (P < 0.05). Twenty patients were followed up for 1 month after leaving the hospital, and there were 5 cases of reappearance of fever, 1 case of increased sleep, 1 case of physical fatigue and 1 case of loss of appetite within 2 weeks.

Conclusions

Paxlovid has no apparent adverse reactions in children 12 years old and younger with underlying hematological diseases infected with the new coronavirus. Focusing on the interaction between paxlovid and other drugs is necessary during the treatment.

Optimizing the use of nirmatrelvir/ritonavir in solid organ transplant recipients with COVID-19: A review of immunosuppressant adjustment strategies

The coronavirus disease 2019 (COVID-19) pandemic has caused a significant burden of morbidity and mortality worldwide, with solid organ transplant recipients (SOTRs) being particularly vulnerable. Nirmatrelvir and ritonavir have demonstrated the potential for reducing the risk of hospitalization and death in patients with mild-to-moderate COVID-19. However, ritonavir has a strong drug–drug interaction with CYP3A-dependent drugs such as calcineurin inhibitors, potentially leading to rapid increases in blood concentration. As SOTRs are commonly prescribed immunosuppressants, co-administration with nirmatrelvir/ritonavir requires careful consideration. To address this issue, we conducted a literature review to evaluate the use and adverse effects of nirmatrelvir/ritonavir in SOTRs and explore feasible immunosuppressant adjustment regimens. Our findings suggest that nirmatrelvir/ritonavir could be a feasible treatment option for COVID-19 in SOTRs, provided that appropriate immunosuppressive drug management is in place during co-administration. Although prescribing the novel anti-SARS-CoV-2 drug to transplant recipients poses challenges, potential strategies to overcome these issues are discussed. Further studies are needed to determine the optimal dosing strategies of nirmatrelvir/ritonavir, immunosuppressant adjustment, and monitoring in this patient population.

Theranostics for COVID-19 Antiviral Drugs: Prospects and Challenges for Worldwide Precision/Personalized Medicine

Coronavirus disease 2019 (COVID-19) is a systemic disease that impacts multiple organ systems with a complex clinical presentation and outcomes that can vary from person to person and between populations. To optimize COVID-19 treatment outcomes, and in light of the availability of antiviral drugs, there is a need for greater attention to the field of theranostics, the fusion of therapeutics and diagnostics. Theranostics tests would be invaluable, we suggest in this expert review, so as to optimize the efficacy and safety of current and future antiviral drugs against COVID-19. Theranostics would also assist in the design and implementation of clinical trials with antiviral drug candidates. We discuss here theranostics considering drugs such as remdesivir, Paxlovid™, and molnupiravir. All in all, we underscore that theranostics as a concept and practice is essential for efficient and safe health interventions against COVID-19 and other ecological crises in the 21st century.

Effectiveness of the available early therapies in reducing severe COVID-19 in non-hospitalized patients with solid tumors on active treatment

Emergency use authorization of drugs against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by regulatory authorities has provided new options to treat high-risk outpatients with mild-to-moderate Coronavirus disease 2019 (COVID-19). We conducted an ambispective cohort study of patients with solid tumors on active treatment to examine the effectiveness of these drugs in preventing the progression to severe COVID-19. Sixty-nine patients with solid tumors (43 women, 26 men; median age 61, range 26–80) reported a laboratory-confirmed diagnosis of SARS-CoV-2 infection. Forty-nine patients received early therapy. Only one patient (14.5%) required hospitalization for COVID-19. As for safety, two patients (5.9%) reported nausea during nirmatrelvir/ritonavir. The majority of treated patients showed a reduced time to negative sample (73 vs. 18%, p = 0.0011) and shorter symptoms’ duration (94 vs. 27%; p < 0.0001) compared to the patients not treated with the early COVID-19 therapies. Our data suggest that early therapies may reduce the morbidity of COVID-19 in patients with solid tumors.