Real-world application of nirmatrelvir/ritonavir in hospitalized COVID-19 patients with onset of symptoms beyond 5 days: a comparative study

PURPOSE

Physicians may administer Nirmatrelvir-ritonavir to patients who have been symptomatic for more than 5 days. There is currently no clear evidence to support this approach.

METHODS

A real-world study was conducted to investigate the potential relationship between the administration of Nirmatrelvir-ritonavir and the rates of intubation or in-hospital mortality among COVID-19 patients who experienced symptoms for more than 5 days. The end point was a composite event of intubation or in-hospital mortality. The outcomes between those patients who received Nirmatrelvir-ritonavir and those who did not were compared.

RESULTS

A total of 847 patients were included in the analysis. Among them, 312 patients (36.84%) received Nirmatrelvir-ritonavir. Within the entire population, 86 patients (10.15%) experienced intubation or in-hospital mortality. The main analysis indicated that there was a significant association between the application of Nirmatrelvir-ritonavir and intubation or in-hospital mortality, with an odds ratio of 0.50 (95% confidence interval, 0.28 to 0.87; P = 0.0153) using inverse probability of treatment weighting. The finding was consistent with multiple sensitivity analyses.

CONCLUSIONS

The application of Nirmatrelvir-ritonavir was associated with a significantly reduced risk of intubation or death in hospitalized COVID-19 patients who experienced symptoms for more than 5 days as compared to those who did not receive the treatment.

Mild SARS-CoV-2 infection in vulnerable patients: implementation of a clinical pathway for early treatment

INTRODUCTION

The objective of this report is to describe the clinical pathway for early treatment of patients with acute SARS-CoV-2 infection and to evaluate the first results of its implementation.

METHODS

This is a descriptive and retrospective study of the implementation of a clinical pathway of treatment in outpatients (January 1 to June 30 2022). Clinical pathway: detection and referral systems from Primary Care, Emergency services, hospital specialities and an automated detection system; clinical evaluation and treatment administration in the COVID-19 day-hospital and subsequent clinical follow-up. Explanatory variables: demographics, comorbidity, vaccination status, referral pathways and treatment administration.

OUTCOME VARIABLES

hospitalization and death with 30 days, grade 2-3 toxicity related to treatment.

RESULTS

Treatment was administered to 262 patients (53,4% women, median age 60 years). The treatment indication criteria were immunosupression (68,3%), and the combination of age, vaccination status and comorbidity in the rest 47,3% of the patients s received remdesivir, 35,9% nirmatrelvir/ritonavir, 13,4% sotrovimab and 2,4% combined treatment with a median of 4 days after symptom onset. Hospital admission was required for 6,1% of the patients, 3,8% related to progression COVID-19. No patient died. Toxicity grade 2-3 toxicity was reported in 18,7%, 89,8% dysgeusia and metallic tasted related nirmatrelvir/ritonavir. Seven patients discontinued treatment due to toxicity.

CONCLUSION

The creation and implementation of a clinical pathway for non-hospitalized patients with SARS-CoV-2 infection is effective and it allows early accessibility and equity of currently available treatments.

Safety, efficacy, and pharmacokinetics of nirmatrelvir and ritonavir in patients with severe COVID-19 and renal impairment: A case report

Nirmatrelvir/ritonavir (N/r) has received emergency use authorization for mild-to-moderate COVID-19 treatment in adult and pediatric patients (aged and weighing at least 12 years and 40 kg, respectively) presenting positive direct SARS-CoV-2 viral testing results and a high risk of disease progression to severe COVID-19. However, information remains limited concerning the corresponding drug safety, efficacy, and pharmacokinetics in patients with severe renal impairment. In this study, we present the case of a 91-year-old Chinese man who, despite exhibiting recurrent positive SARS-CoV-2 results and progression to severe COVID-19, was treated with N/r. Due to severe renal impairment and concurrent administration of continuous renal replacement therapy (continuous venovenous hemofiltration) during medication, we aimed to determine the serum N/r drug concentration in the patient. Our analysis revealed Cmax values of 12.42 and 2.001 μg/mL for nirmatrelvir and ritonavir, respectively. Despite the particularly high serum N/r concentration in this patient, the clinical and laboratory test analyses confirmed that the treatment was safe and effective. Nevertheless, N/r should be used with caution and at lower doses in patients with severe renal impairment to avoid potential high N/r concentration-related adverse reactions and events.

[Translated article] Safety profile of nirmatrelvir-ritonavir: Evidence of adverse events due to DDIs

OBJECTIVE

The aim of the study was to evaluate the safety profile of nirmatrelvir-ritonavir (NMV-r) in real clinical practice and to analyse the clinical relevance of drug-drug interactions in the development of adverse events.

METHODS

Observational, retrospective study in which safety data of patients treated with NMV-r between April and July 2022 in an outpatient setting were evaluated. The duration of follow-up was 28 days and the number of adverse reactions reported, as well as whether they were managed on an outpatient basis or required health care, and the presence of renal and hepatic function impairment were assessed. Concomitant treatment was reviewed, identifying theoretical drug-drug interactions (TDDIs) whose severity was defined using the Lexi-interact classification.

RESULTS

The study included 146 patients. 82 (56.16%) were women, whose median age was 65 years (22-95). the number of TDDIs detected and maintained during treatment with NMV-r was 164, with the percentage of patients with at least 1 interaction being 62.33%. The median number of TDDIs per patient was 1 (0-5). At least 1 adverse event (AE) was reported in 18 patients (11.84%). 11 AEs were potentially related to any TDDI. 7 patients required contact with hospital assistance for AE management. 8 patients had impaired renal function and 2 had impaired liver function at 28 days. The main groups of drugs implicated in the occurrence of an AE were oral anticoagulants and calcium antagonists.

CONCLUSIONS

Our results show a high number of TDDIs detected were detected between NMV-r and other drugs. This study provides greater knowledge of the drugs involved in such interactions and their potential relationship with the occurrence of adverse events.

Safety profile of nirmatrelvir-ritonavir: Evidence of adverse events due to drug-drug interactions

OBJECTIVE

The aim of the study was to evaluate the safety profile of nirmatrelvir-ritonavir (NMV-r) in real clinical practice and to analyze the clinical relevance of drug-drug interactions in the development of adverse events.

METHODS

Observational, retrospective study in which safety data of patients treated with NMV-r between April and July 2022 in an outpatient setting were evaluated. The duration of follow-up was 28 days and the number of adverse reactions reported, as well as whether they were managed on an outpatient basis or required health care, and the presence of renal and hepatic function impairment were assessed. Concomitant treatment was reviewed, identifying theoretical drug-drug interactions (TDDIs) whose severity was defined using the Lexi-interact classification.

RESULTS

The study included 146 patients, 82 (56,16%) were women, whose median age was 65 years (22-95). The number of TDDIs detected and maintained during treatment with NMV-r was 164, with the percentage of patients with at least one interaction being 62,33%. The median number of TDDIs per patient was 1 (0-5). At least 1 adverse event (AE) was reported in 18 patients (11,84%). Eleven AEs were potentially related to any TDDI. Seven patients required contact with hospital assistance for AE management. Eight patients had impaired renal function and 2 had impaired liver function at 28 days. The main groups of drugs implicated in the occurrence of an AE were oral anticoagulants and calcium antagonists.

CONCLUSIONS

Our results show a high number of TDDIs detected were detected between NMV-r and other drugs. This study provides greater knowledge of the drugs involved in such interactions and their potential relationship with the occurrence of adverse events.

Antiviral effectiveness and survival correlation of azvudine and nirmatrelvir/ritonavir in elderly severe patients with COVID-19: a retrospective real-world study

Background

Azvudine and nirmatrelvir/ritonavir are approved to treat mild-to-moderate coronavirus disease 2019 (COVID-19) in adults with a high risk for progression to severe infection. We sought to compare the antiviral effectiveness and clinical outcomes of elderly severe patients with COVID-19 receiving these two antiviral agents.

Methods

In this observational study, we identified 249 elderly patients with severe COVID-19 infection who were admitted to the Second Medical Center of the People's Liberation Army General Hospital from December 2022 to January 2023, including 128 azvudine recipients, 66 nirmatrelvir/ritonavir recipients and 55 patients not received antiviral treatments. We compared the cycle threshold (Ct) value dynamic change of all three groups. The primary outcome was a composite outcome of disease progression, including all-cause death, intensive care unit admission, and initiation of invasive mechanical ventilation. The outcomes of all enrolled patients were followed up from the electronic medical record system. Kaplan-Meier and Cox risk proportional regression analyses were used to compare the clinical outcomes of all three groups. To more directly compare the effectiveness of the two antiviral drugs, we performed propensity-score matching between the two antiviral groups and compared antiviral efficacy and clinical outcomes in the matched population.

Findings

Among 249 patients (mean age, 91.41 years), 77 patients died during the follow-up period. When compared to patients who did not receive any antivirals, neither nirmatrelvir/ritonavir nor azvudine demonstrated a survival benefit. The Cox analysis of the all-cause death of the three groups showed that the risk of death was 0.730 (0.423-1.262) in the azvudine group 0.802 (0.435-1.480) and in the nirmatrelvir/ritonavir group compared with the non-antiviral group. After propensity score matching, we included 58 azvudine recipients and 58 nirmatrelvir/ritonavir recipients. The fitted curve of the Ct value after matching illustrated that the rate of viral decline in the early stage of nirmatrelvir/ritonavir treatment seems to surpass that of azvudine, but there was no statistical significance. Azvudine was seemly associated with a lower risk of composite outcomes (HR:1.676, 95% CI:0.805-3.488) and short-term all-cause death (HR: 1.291, 95%CI: 0.546-3.051).

Interpretation

Patients who received azvudine have a similar antiviral effectiveness and survival curve trend compared to nirmatrelvir/ritonavir. In this limited series, antiviral treatment was not associated with a significant clinical benefit. This lack of clinical benefit might be attributed to potential bias.

Funding

This study was supported by the "National Key R&D Program of China" (Funding No. 2020YFC2008900) and the National Defense Science and Technology Innovation Special Zone Project (223-CXCY-N101-07-18-01).

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.

Detailed tracking of antigen and antibody levels during coronavirus disease 2019 treatment in an immunosuppressed patient with anti-neutrophil cytoplasmic autoantibody-associated vasculitis

A 67-year-old woman with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis was not vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was on multiple immunosuppressive drugs. She was hospitalized because of interstitial shadowing in the lungs and diagnosed with persistent coronavirus disease 2019 (COVID-19). Despite treatment with a recombinant monoclonal antibody and antivirals, her symptoms persisted and she lacked a specific antibody response. She tested negative for SARS-CoV-2 antigen after the second antiviral treatment, and a subsequent chest radiograph showed improvement. However, the antibody levels did not change. This case highlights the importance of careful monitoring of the SARS-CoV-2 antigen and antibody levels during COVID-19 treatment in patients with immunosuppression.

Comparison of azvudine, molnupiravir, and nirmatrelvir/ritonavir in adult patients with mild-to-moderate COVID-19: a retrospective cohort study

This study aimed to explore the effectiveness and safety of azvudine, nirmatrelvir/ritonavir, and molnupiravir in adult patients with mild-to-moderate COVID-19. This retrospective cohort study included patients with mild-to-moderate COVID-19 (asymptomatic, mild, and common types) at the First Hospital of Changsha (Hunan Province, China) between March and November 2022. Eligible patients were classified into the azvudine, nirmatrelvir/ritonavir, or molnupiravir groups according to the antiviral agents they received. The outcomes were the times to nucleic acid negative conversion (NANC). This study included 157 patients treated with azvudine (n = 66), molnupiravir (n = 66), or nirmatrelvir/ritonavir (n = 25). There were no statistically significant differences in the time from diagnosis to NANC among the azvudine, molnupiravir, and nirmatrelvir/ritonavir groups [median, 9 (95% CI 9-11) vs. 11 (95% CI 10-12) vs. 9 (95% CI 8-12) days, P = 0.15], time from administration to NANC [median, 9 (95% CI 8-10) vs. 10 (95% CI 9.48-11) vs. 8.708 (95% CI 7.51-11) days, P = 0.50], or hospital stay [median, 11 (95% CI 11-13) vs. 13 (95% CI 12-14) vs. 12 (95% CI 10-14) days, P = 0.14], even after adjustment for sex, age, COVID-19 type, comorbidities, Ct level, time from diagnosis to antiviral treatment, and number of symptoms. The cumulative NANC rates in the azvudine, molnupiravir, and nirmatrelvir/ritonavir groups were 15.2%/12.3%/16.0% at day 5 (P = 0.858), 34.8%/21.5%/32.0% at day 7 (P = 0.226), 66.7%/52.3%/60.0% at 10 days (P = 0.246), and 86.4%/86.2%/80.0% at day 14 (P = 0.721). No serious adverse events were reported. Azvudine may be comparable to nirmatrelvir/ritonavir and molnupiravir in adult patients with mild-to-moderate COVID-19 regarding time to NANC, hospital stay, and AEs.

Cost-effectiveness of nirmatrelvir/ritonavir for high-risk adult outpatients with COVID-19 in Japan

INTRODUCTION

This study aimed to evaluate the cost-effectiveness of nirmatrelvir/ritonavir (Nir/Rit) for adult outpatients with COVID-19 from the perspective of a Japanese public healthcare payer.

METHODS

A cost-effectiveness simulation was conducted comparing Nir/Rit for the outpatient treatment of high-risk COVID-19 patients to best supportive care (BSC) without antiviral or antibody drugs. The analytical model was divided into two phases: the treatment phase, lasting 35 days from the start of COVID-19 treatment, and the post-treatment phase. Patients who survived the treatment phase were assumed to follow a general population survival curve. Expected costs and expected quality-adjusted life years (QALYs) for both BSC and Nir/Rit were calculated for ages 40 to 80 to obtain the incremental cost-effectiveness ratio (ICER). The robustness of the results was evaluated through deterministic and probabilistic sensitivity analysis (PSA).

RESULTS

The ICERs for patients aged 40, 50, 60, 70, and 80 were 18,854,276 Japanese Yen (JPY)/QALY, 8,482,034 JPY/QALY, 4,976,612 JPY/QALY, 2,636,096 JPY/QALY, and 1,597,783 JPY/QALY, respectively. In the deterministic sensitivity analysis, both the mortality risk during the treatment phase and the relative mortality risk with Nir/Rit had a high impact on ICER across all ages. In the PSA, when the willingness-to-pay (WTP) threshold was set at 5 million JPY/QALY, the probability of the ICER being below the WTP threshold was 0%, 0.2%, 45.4%, 99.9%, and 100% at ages 40, 50, 60, 70, and 80, respectively.

CONCLUSION

Nir/Rit is cost-effective for older individuals aged 60 and over but not for younger age groups.

Acute acalculous cholecystitis following extended administration of nirmatrelvir/ritonavir for persistent SARS-CoV-2 infection

Immunocompromised patients with hematologic malignancies, particularly those treated with anti-CD20 antibodies such as rituximab and obinutuzumab, are known to be at risk of prolonged infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Prolonged administration or combination therapy with antiviral medications reportedly yields favorable outcomes in these patients. However, knowledge regarding the adverse events associated with such therapeutic approaches is limited. Herein, we report a case of acute acalculous cholecystitis (AAC) following extended administration of nirmatrelvir/ritonavir (NMV/r) in a 68-year-old Japanese man with persistent SARS-CoV-2 infection. The patient had received obinutuzumab and bendamustine for follicular lymphoma and was diagnosed with coronavirus disease 2019 (COVID-19) approximately one year after treatment initiation with these drugs. Subsequently, he was admitted to a different hospital, where he received antiviral drugs, monoclonal antibodies, and steroids. Despite these interventions, the patient relapsed and was subsequently transferred to our hospital due to persistent SARS-CoV-2 infection. Remdesivir administration was ineffective, leading to the initiation of extended NMV/r therapy. One week later, he exhibited elevated gamma-glutamyl transpeptidase (GGT) levels, and one month later, he developed AAC. Cholecystitis was successfully resolved via percutaneous transhepatic gallbladder drainage and administration of antibiotics. We speculate that extended NMV/r administration, in addition to COVID-19, may have contributed to the elevated GGT and AAC. During treatment of persistent SARS-CoV-2 infection with extended NMV/r therapy, patients should be carefully monitored for the appearance of findings suggestive of biliary stasis and the development of AAC.

Effectiveness and safety of azvudine in older adults with mild and moderate COVID-19: a retrospective observational study

BACKGROUND

Azvudine has clinical benefits and acceptable safety against COVID-19, including in patients with comorbidities, but there is a lack of available data for its use in older adult patients. This study explored the effectiveness and safety of azvudine in older adults with mild or moderate COVID-19.

METHODS

This retrospective cohort study included patients aged ≥80 diagnosed with COVID-19 at the Central Hospital of Shaoyang between October and November 2022. According to the therapies they received, the eligible patients were divided into the azvudine, nirmatrelvir/ritonavir, and standard-of-care (SOC) groups. The outcomes were the proportion of patients progressing to severe COVID-19, time to nucleic acid negative conversion (NANC), and the 5-, 7-, 10-, and 14-day NANC rates from admission.

RESULTS

The study included 55 patients treated with azvudine (n = 14), nirmatrelvir/ritonavir (n = 18), and SOC (n = 23). The median time from symptom onset to NANC of the azvudine, nirmatrelvir/ritonavir, and SOC groups was 14 (range, 6-25), 15 (range, 11-24), and 19 (range, 18-23) days, respectively. The median time from treatment initiation to NANC of the azvudine and nirmatrelvir/ritonavir groups was 8 (range, 4-20) and 9 (range, 5-16) days, respectively. The median length of hospital stay in the three groups was 10.5 (range, 5-23), 13.5 (range, 10-21), and 17 (range, 10-23) days, respectively. No treatment-related adverse events or serious adverse events were reported.

CONCLUSION

Azvudine showed satisfactory effectiveness and acceptable safety in older adults with mild or moderate COVID-19. Therefore, azvudine could be a treatment option for this special patient population.

High concentrations of nirmatrelvir/ritonavir in critically ill patients receiving continuous renal replacement therapy

OBJECTIVES

Nirmatrelvir/ritonavir is a highly efficacious agent against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Although dose adjustment is recommended in patients with renal impairment according to the package insert for Paxlovid (Pfizer), there is no dose recommendation for patients with severe renal impairment who require continuous renal replacement therapy (CRRT).

METHODS

To characterise the features of nirmatrelvir/ritonavir in critically ill Chinese patients undergoing CRRT, therapeutic drug monitoring of nirmatrelvir/ritonavir was performed by high-performance liquid chromatography tandem mass spectrometry assay in eight patients.

RESULTS

Nirmatrelvir trough concentrations ranged from 3325.34 ng/mL to 15 625.46 ng/mL. Concentrations were up to 7-fold higher compared with patients with normal renal function and 2-fold higher compared with patients with end-stage renal disease undergoing haemodialysis.

CONCLUSIONS

These results suggest that a dose reduction should be implemented in the treatment of patients with CRRT.

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.

Effect of pre-hospitalization use of oral antiviral agents on reducing critical illness and mortality for patients with COVID-19 pneumonia

OBJECTIVES

This study aimed to evaluate the effect of administering nirmatrelvir/ritonavir and molnupiravir before hospitalisation on subsequent critical illness among patients with COVID-19 pneumonia.

METHODS

This retrospective cohort study included patients with COVID-19 pneumonia who required hospitalisation between 1 January 1 2022 and 31 August 2022. The primary outcomes were the development of critical illness, including intensive care unit admission, use of mechanical ventilation, or mortality. A multivariate logistic regression analysis was conducted to assess the varying risks of critical illness and mortality. A total of 1,011 COVID-19 patients were analysed. Among them, 304 (30.1%) received molnupiravir and 131 (13.0%) received nirmatrelvir/ritonavir before hospitalisation.

RESULTS

There were significant reductions for critical illness (adjusted odds ratio 0.29, 95% confidence interval 0.21-0.39, P < 0.001) and mortality (adjusted odds ratio 0.40, 95% confidence interval 0.27-0.59, P < 0.001) in patients receiving oral antivirals compared with those who did not. No significant differences in critical illness were observed between molnupiravir and nirmatrelvir/ritonavir. The combination of COVID-19 vaccines and oral antivirals can further reduce the risk of critical illness in high-risk populations.

CONCLUSION

Administering molnupiravir and nirmatrelvir/ritonavir before hospitalisation reduced the risk of COVID-19 patients with moderate to severe pneumonia progressing to critical illness and mortality.

Nirmatrelvir/Ritonavir Utilization for the Treatment of Non-hospitalized Adults with COVID-19 in the National Veterans Affairs (VA) Healthcare System

INTRODUCTION

Limited data exist regarding real-world utilization of nirmatrelvir/ritonavir. We identified predictors of nirmatrelvir/ritonavir use among Veterans Affairs (VA) outpatients nationally.

METHODS

We conducted a retrospective cohort study among outpatients with coronavirus disease 2019 (COVID-19) who were eligible to receive nirmatrelvir/ritonavir between January and December of 2022, to identify factors associated with nirmatrelvir/ritonavir use (i.e., demographics, medical history, prior medication and healthcare exposures, frailty, and other clinical characteristics) using multivariable logistic regression.

RESULTS

We included 309,755 outpatients with COVID-19 who were eligible for nirmatrelvir/ritonavir, of whom 12.2% received nirmatrelvir/ritonavir. Nirmatrelvir/ritonavir uptake increased from 1.1% to 23.2% over the study period. Factors associated with nirmatrelvir/ritonavir receipt included receiving a COVID-19 booster vs. none (adjusted odds ratio [aOR] 2.19 [95% confidence interval [CI] 2.12-2.26]), age ≥ 50 vs. 18-49 years (aORs > 1.5 for all age groups ≥ 50 years), having HIV (aOR 1.36 [1.22-1.51]), being non-frail vs. severely frail (aOR 1.22 [1.13-1.33]), and having rheumatoid arthritis (aOR 1.12 [1.04-1.21). Those with concomitant use of potentially interacting antiarrhythmics (aOR 0.35 [0.28-0.45]), anticoagulants/antiplatelets (aOR 0.42 [0.40-0.45]), and/or psychiatric/sedatives (aOR 0.84 [0.81-0.87]) were less likely to receive nirmatrelvir/ritonavir.

CONCLUSIONS

Despite increases over time, overall utilization of nirmatrelvir/ritonavir was low. Predictors of nirmatrelvir/ritonavir utilization were consistent with known risk factors for progression to severe COVID-19, including older age and underlying medical conditions. Unvaccinated and undervaccinated patients and those receiving potentially interacting medications for cardiovascular or mental health conditions (antiarrhythmic, alpha-1 antagonist, anticoagulant/antiplatelet, sedative/hypnotic/psychiatric) were less likely to receive nirmatrelvir/ritonavir. Further education of prescribers and patients about nirmatrelvir/ritonavir treatment guidelines is needed to improve overall uptake and utilization in certain high-risk subpopulations.

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.

Nirmatrelvir/ritonavir use in patients with COVID-19 on hemodialysis: a case series

Patients undergoing hemodialysis (HD) are particularly vulnerable to coronavirus disease 2019 (COVID-19) and are at increased risk of developing severe infection. However, given the exclusion of such patients from clinical trials, there are limited data regarding the effectiveness of the antiviral drug nirmatrelvir/ritonavir (N/R) in patients on HD. We prescribed N/R to 4 patients on HD with COVID-19 after obtaining informed consent. Their clinical symptoms were improved at approximately 3 days after N/R administration. The viral load was reduced after approximately 10 days. The main adverse effects were nausea and vomiting. Rational dosage adjustment obtained good tolerance but did not influence the efficacy. These results suggest that N/R may be a promising agent for patients on HD with COVID-19.

Strategies to Mitigate the Drug-Drug Interaction between Nirmatrelvir/Ritonavir and Tacrolimus in Allogeneic Hematopoietic Stem Cell Transplant Recipients on Azole Antifungals: Results of a Case Series

INTRODUCTION

Nirmatrelvir/ritonavir (NIM/r) inhibits tacrolimus metabolism resulting in a profound drug-drug interaction that is further complicated by the use of azole antifungals.

CASE PRESENTATIONS

We describe three strategies, in 4 patient cases, for the initiation of NIM/r in allogeneic hematopoietic stem cell transplant (alloHSCT) recipients on tacrolimus at the time of diagnosis. Patients 1 and 2 (strategy 1) experienced prolonged, elevated tacrolimus concentrations after an empiric 33% reduction in tacrolimus dose and adjustment of azole antifungal at NIM/r initiation (strategy 1) and with complete discontinuation of tacrolimus and azole antifungal at NIM/r initiation (strategy 2). Patients 3 and 4 (strategy 3) did not experience elevated tacrolimus concentrations on NIM/r treatment with complete discontinuation of tacrolimus and azole antifungal and a 12-24-h delay in NIM/r initiation. Reinitiation of tacrolimus after NIM/r completion resulted in variable tacrolimus concentrations.

CONCLUSION

NIM/r-tacrolimus is a serious drug-drug interaction which can be mitigated by early discontinuation of tacrolimus and azole antifungals, close monitoring, and reinitiation of tacrolimus and antifungal 48-72 h after completion of therapy.

Drug treatment for Covid-19 - three years later

There has been a profusion of trials for SARS CoV2 drugs. A review dating from May 2020 listed 115 medicines, most of which previously existed, having been investigated since the onset of the pandemic. Over an exceedingly short lapse of time, the perspective of the arrival of a new antiviral treatment specifically targeting COVID-19 appeared highly improbable. Three years later, only one treatment is recommended in France: the nirmatrelvir + ritonavir combination. While remdesivir remains available, it is only proposed when this combination is officially contraindicated. Three monoclonal antibodies, taken alone or in association, are currently available in France:: tixagevimab/cilgavimab, casirivimab/imdevimab and sotrovimab. While all three of them have received European market authorization for patients presenting with an increased risk of evolution toward a severe form of COVID-19, and while early access is possible, they are no longer recommended, the reason being a loss or alteration of activity on variants carrying a Spike protein mutation. RoActemra is a humanized monoclonal antibody that blocks the action of interleukin 6 receptors; it is exclusively reserved for adult patients receiving systemic corticotherapy and necessitating oxygen supplementation, while patients under invasive mechanical ventilation are excluded. All in all, since the onset of the pandemic dozens of products have been subjected to tests or trials; three years later, only a highly limited number of "candidates" remain, and definitive assessment has yet to be achieved.

Nirmatrelvir/ritonavir (Paxlovid®): French pharmacovigilance survey 2022

INTRODUCTION

Nirmatrelvir/ritonavir (Paxlovid®) is currently one of the few therapeutic options for coronavirus disease 2019 (COVID-19) curative treatment in non-oxygen-requiring adult patients at-high risk of progressing to severe disease. This recently approved boosted antiviral therapy presents a significant risk of drug-drug interactions (DDI). As part of the enhanced surveillance program in France for COVID-19 drugs and vaccines, the French national pharmacovigilance database (BNPV [base nationale de pharmacovigilance]) was queried in order to better characterize the drug safety profile, with a special focus on DDI. The aim of the study was to describe the adverse drug reactions reported through the BNPV.

METHOD

All nirmatrelvir/ritonavir reports validated in the BNPV from the first authorization in France (January, 20th 2022) to December, 3rd 2022 (date of the query) were considered. An analysis of the scientific literature (PubMed®) and from the WHO pharmacovigilance database (Vigibase) was also performed.

RESULTS

Over this period (11 months), 228 reports (40% of serious reports) were registered with a sex ratio of 1.9 female/1 male and a mean age of 66 years old. DDI reports account for more than 13% of reports (n=30) and were mainly related to immunosuppressive drugs overexposure (n=16). A total of 10/228 reports with fatal outcomes were reported in complex clinical settings. The main reported unexpected adverse drug reaction (ADRs) were high blood pressure (n=7), confusion (n=5), acute kidney injuries (AKI, n=7) and various skin reactions (n=22). Apart from situations of disease recurrence (not found in this analysis), data from Pubmed® and Vigibase also reported the above-mentioned events of interest.

CONCLUSION

Overall, this analysis shows that nirmatrelvir/ritonavir safety profile was conform to current summary of product characteristics (SmPC). The main concern was the risk of DDI. Therefore, SmPC and expert recommendations should be systematically consulted before initiation of this antiviral, which is particularly indicated in polypharmacy patients. A case-by-case multidisciplinary approach including a clinical pharmacologist is required in these complex situations. Blood pressure elevation, confusion, cutaneous reactions and AKIs were the main unexpected ADRs of interest to follow, but need to be confirmed with a qualitative approach over time and new reports.

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.

Real-life comparison of mortality in patients with SARS-CoV-2 infection at risk for clinical progression treated with molnupiravir or nirmatrelvir plus ritonavir during the Omicron era in Italy: a nationwide, cohort study

Background

Comparative data on mortality in COVID-19 patients treated with molnupiravir or with nirmatrelvir plus ritonavir are inconclusive. We therefore compared all-cause mortality in community-dwelling COVID-19 patients treated with these drugs during the Omicron era.

Methods

Data collected in the nationwide, population-based, cohort of patients registered in the database of the Italian Medicines Agency (AIFA) were used. To increase completeness of the recorded deaths and date correctness, a cross-check with the National Death Registry provided by the Ministry of the Interior was performed. We included in this study all patients infected by SARS-CoV-2 treated within 5 days after the test date and symptom onset between February 8 and April 30, 2022. All-cause mortalities by day 28 were compared between the two treatment groups after balancing for baseline characteristics using weights obtained from a gradient boosting machine algorithm.

Findings

In the considered timeframe, 17,977 patients treated with molnupiravir and 11,576 patients with nirmatrelvir plus ritonavir were included in the analysis. Most patients (25,617/29,553 = 86.7%) received a full vaccine course including the booster dose. A higher crude incidence rate of all-cause mortality was found among molnupiravir users (51.83 per 100,000 person-days), compared to nirmatrelvir plus ritonavir users (22.29 per 100,000 person-days). However, molnupiravir-treated patients were older than those treated with nirmatrelvir plus ritonavir and differences between the two populations were found as far as types of co-morbidities were concerned. For this reason, we compared the weight-adjusted cumulative incidences using the Aalen estimator and found that the adjusted cumulative incidence rates were 1.23% (95% CI 1.07%-1.38%) for molnupiravir-treated and 0.78% (95% CI 0.58%-0.98%) for nirmatrelvir plus ritonavir-treated patients (adjusted log rank p = 0.0002). Moreover, the weight-adjusted mixed-effect Cox model including Italian regions and NHS centers as random effects and treatment as the only covariate confirmed a significant reduced risk of death in patients treated with nirmatrelvir plus ritonavir. Lastly, a significant reduction in the risk of death associated with nirmatrelvir plus ritonavir was confirmed in patient subgroups, such as in females, fully vaccinated patients, those treated within day 2 since symptom onset and patients without (haemato)-oncological diseases.

Interpretation

Early initiation of nirmatrelvir plus ritonavir was associated for the first time with a significantly reduced risk of all-cause mortality by day 28 compared to molnupiravir, both in the overall population and in patient subgroups, including those fully vaccinated with the booster dose.

Funding

This study did not receive funding.

Estimation of Intangible Costs for Factors Associated with Oral Antiviral Drugs for COVID-19 Treatment: A Conjoint Analysis in Japan

INTRODUCTION

During the recent coronavirus disease 2019 (COVID-19) pandemic, preferences for factors associated with vaccines have been evaluated. Three oral antiviral drugs have been approved in Japan for patients with mild-to-moderate I COVID-19 symptoms. Although preferences for the drugs may also depend on various factors, these have not been fully evaluated.

METHODS

A conjoint analysis was performed based on an online survey in August 2022 to estimate the intangible costs of factors associated with oral antiviral drugs for COVID-19. Respondents were individuals aged 20-69 across Japan. The attributes included the company (Japanese/foreign) that developed the drug, formulation and size of the drug, frequency of administration per day, number of tablets/capsules per dose, number of days until no longer infectious to others, and out-of-pocket expenses. A logistic regression model was applied to estimate the utility of each level for each attribute. The intangible costs were calculated by comparing the utility to the out-of-pocket attribute.

RESULTS

Responses were collected from 11,303 participants. The difference between levels was the largest for companies that developed a drug; the intangible costs were JPY 5390 higher for the foreign company than for the Japanese company. The next largest difference was in the number of days until one is no longer infectious. For the same formulation, the intangible cost was lower for small sizes than large sizes. For similar-sized tablets and capsules, the intangible cost was lower for tablets than capsules. These tendencies were similar regardless of COVID-19 infection history and the presence of risk factors for severe COVID-19 in the respondents.

CONCLUSION

Intangible costs for factors associated with oral antiviral drugs among the Japanese population were estimated. The results may change as the number of people with a history of COVID-19 infection increases and significant progress is made regarding treatments.

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.

Preclinical discovery and development of nirmatrelvir/ritonavir combinational therapy for the treatment of COVID-19 and the lessons learned from SARS-COV-2 variants

INTRODUCTION

Nirmatrelvir/ritonavir (Paxlovid®) represent an oral antiviral therapy approved for the treatment of COVID-19. Extensive in vitro and in vivo studies have reported the promising activity of nirmatrelvir/ritonavir against numerous emerging viruses. This combination consists of nirmatrelvir, a protease reversible inhibitor of coronavirus 3CLpro mainly metabolized by cytochrome P450 (CYP)3A4, and ritonavir, an inhibitor of the CYP3A isoforms that enhances the efficacy of nirmatrelvir by fixing its suboptimal pharmacokinetic properties.

AREAS COVERED

This review comprehensively examines the efficacy of nirmatrelvir/ritonavir through rigorous analysis of in vitro and in vivo studies. Moreover, it thoroughly assesses its safety, tolerability, pharmacokinetics, and antiviral efficacy against SARS-COV-2 infection, based on the main pre-authorization randomized controlled trials.

EXPERT OPINION

Nirmatrelvir/ritonavir has a good tolerability profile. Its administration during the early stages of mild-to-moderate COVID-19 holds potential benefits, as it can help prevent the onset of an aberrant immune response that could lead to pulmonary and extra-pulmonary complications. However, its drug - drug interactions can be a factor limiting its use, at least in populations on some chronic therapies, along with the risk of infection relapse after treatment.

Nirmatrelvir/ritonavir treatment in SARS-CoV-2 positive kidney transplant recipients - a case series with four patients

BACKGROUND

Despite vaccination coronavirus disease 2019 (COVID-19)-associated mortality caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains high in kidney transplant recipients. Nirmatrelvir is a protease inhibitor with activity against SARS-CoV-2. Nirmatrelvir reduces the risk for mortality and hospitalization, which is approved for treating adults at risk for severe disease. Nirmatrelvir is metabolized by the cytochrome P-450 (CYP) 3A4 isozyme CYP3A4 and is therefore co-administered with the irreversible CYP3A4 inhibitor ritonavir, which results in a drug interaction with tacrolimus. A limited number of patients with nirmatrelvir/ritonavir and tacrolimus therapy after kidney transplantation have been reported to date. It has been reported that tacrolimus was paused during the five-day nirmatrelvir/ritonavir therapy and subtherapeutic tacrolimus levels were observed after finishing nirmatrelvir/ritonavir in two patients. Therefore, optimization of tacrolimus dosing is urgently needed in transplant recipients receiving nirmatrelvir/ritonavir treatment.

CASE PRESENTATION

Here, we present our first-hand experience with four patients receiving tacrolimus therapy following kidney transplantation and nirmatrelvir/ritonavir therapy due to COVID-19. Tacrolimus was paused during nirmatrelvir/ritonavir therapy in all patients, which resulted in stable therapeutic tacrolimus levels. Tacrolimus was continued directly after finishing nirmatrelvir/ritonavir to avoid subtherapeutic levels in the first patient treated. This patient received his usual tacrolimus maintenance dose, which resulted in toxic levels. Based on this observation, tacrolimus therapy was continued 24 h after finishing nirmatrelvir/ritonavir treatment at a reduced dose in the subsequent patients. In these patients, therapeutic to supratherapeutic tacrolimus levels were observed despite the therapeutic break and dose reduction.

DISCUSSION AND CONCLUSIONS

Based on altered CYP3A4 metabolism, tacrolimus levels have to be closely monitored after treatment with nirmatrelvir/ritonavir. Our study suggests that tacrolimus treatment should be paused during nirmatrelvir/ritonavir medication and be continued 24 h after completing nirmatrelvir/ritonavir therapy at a reduced dose and under close monitoring. Based on the limited number of patients in this study, results must be interpreted with caution.

A case report of a prolonged decrease in tacrolimus clearance due to co-administration of nirmatrelvir/ritonavir in a lung transplant recipient receiving itraconazole prophylaxis

BACKGROUND

Drug-drug interaction management is complex. Nirmatrelvir/ritonavir is a potent cytochrome P450 (CYP) 3A inhibitor and influences pharmacokinetics of co-administered drugs. Although there are several reports about drug-drug interactions of nirmatrelvir/ritonavir, an influence of a concomitant use of nirmatrelvir/ritonavir and another potent CYP3A inhibitor on tacrolimus remains unclear. Here, we experienced a lung transplant patient with the novel coronavirus disease 2019 (COVID-19). In this patient, nirmatrelvir/ritonavir was administered, and the inhibitory effect of itraconazole on CYP3A was prolonged.

CASE PRESENTATION

We present a case in forties who had undergone lung transplantation. He was administered itraconazole and tacrolimus 1.0 mg/d, with a trough value of 8-12 ng/mL. The patient contracted the COVID-19, and a nirmatrelvir/ritonavir treatment was initiated. During the antiviral treatment, tacrolimus administration was discontinued for 5 d. Tacrolimus was resumed at 1.0 mg/d after completion of the nirmatrelvir/ritonavir treatment, but the trough value after 7 d was high at 31.6 ng/mL. Subsequently, the patient was placed on another 36-h tacrolimus discontinuation, but the trough value decreased to only 16.0 ng/mL.

CONCLUSIONS

Co-administration of ritonavir caused a prolonged decrease in tacrolimus clearance through its inhibitory effects on CYP3A in a patient taking itraconazole. Management of drug-drug interaction by pharmacists can be important for patients with multiple medications.

Characteristics and outcomes of US Veterans at least 65 years of age at high risk of severe SARS-CoV-2 infection with or without receipt of oral antiviral agents

OBJECTIVES

Molnupiravir and nirmatrelvir/ritonavir each became available in the United States (US) through the Food and Drug Administration (FDA) emergency use authorization (EUA) in December 2021 after their respective initial prospective randomized controlled trials demonstrated efficacy for patients with mild-to-moderate SARS-CoV-2 active infection considered to be at high risk for progression of disease and hospitalization. Although sufficiently powered for this wide group, the mean age for patients in these studies was only 43 and 46 years of age, respectively. We sought to compare outcomes of US Veterans 65 years and older who received either of these oral antivirals to those who did not receive oral antivirals for mild-to-moderate SARS-CoV-2 active infection.

METHODS

The current project was a retrospective, observational, nationwide propensity-matched analysis comparing outcomes of US Veterans 65 years and older who received either of these oral antivirals to US Veterans 65 years and older who did not receive oral antivirals for mild-to-moderate SARS-CoV-2 active infection.

RESULTS

The composite primary outcome of admission or death within 30 days of diagnosis was reached less often in those receiving either molnupiravir or nirmatrelvir/ritonavir versus those that received no antiviral (65/1370 [4.75%] vs. 139/1370 [10.2%]; odds ratio 0.44, 95% confidence interval 0.32-0.60, p<0.0001). Baseline differences between Veterans selected for molnupiravir vs. nirmatrelvir/ritonavir therapy were noted, particularly in the number of concomitant medications with cautions or contraindications with nirmatrelvir/ritonavir.

CONCLUSIONS

Our findings support the use of molnupiravir or nirmatrelvir/ritonavir in patients 65 years of age and older. Patients with higher medication caution and contraindication burdens to nirmatrelvir/ritonavir are selected for molnupiravir therapy, which in the absence of a prospective head-to-head trial, may limit any efforts to compare the effectiveness of the two drugs.

[Translated article] Paradoxical interaction between nirmatrelvir/ritonavir and voriconazole in a patient with COVID-19

This case is based on a drug interaction between nirmatrelvir/ritonavir (approved drug for COVID-19) and voriconazole is presented, possibly derived from the bidirectional effect of ritonavir on the 2 main voriconazole metabolizing enzymes (cytochrome P450 3A and 2C19) ritonavir inhibits the former and induces the latter respectively. According to the main pharmacotherapeutic information databases, in the interaction between both drugs, a decrease in the area under the curve of voriconazole is expected due to the inducing effect of its metabolism; however, in the case we present, unexpectedly, a paradoxical effect occurs, according to what is described in literature, with the result of sustained supratherapeutic levels of voriconazole. Given the short treatment period with nirmatrelvir/ritonavir (5 days), the induction effect of ritonavir proposed in the studies on which the recommendations are based, where treatment with ritonavir is longer, does not occur.

Paradoxical interaction between nirmatrelvir/ritonavir and voriconazole in a patient with COVID-19

This case is based on a drug interaction between nirmatrelvir/ritonavir (approved drug for COVID-19) and voriconazole is presented, possibly derived from the bidirectional effect of ritonavir on the 2 main voriconazole metabolising enzymes (cytochrome P450 3A and 2C19) ritonavir inhibits the former and induces the latter respectively. According to the main pharmacotherapeutic information databases, in the interaction between both drugs, a decrease in the area under the curve of voriconazole is expected due to the. inducing effect of its metabolism; however, in the case we present, unexpectedly, a paradoxical effect occurs, according to what is described in literature, with the result of sustained supratherapeutic levels of voriconazole. Given the short treatment period with nirmatrelvir/ritonavir (5 days), the induction effect of ritonavir proposed in the studies on which the recommendations are based, where treatment with ritonavir is longer, does not occur.

Efficacy and Safety of Nirmatrelvir/Ritonavir, Molnupiravir, and Remdesivir in a Real-World Cohort of Outpatients with COVID-19 at High Risk of Progression: The PISA Outpatient Clinic Experience

INTRODUCTION

Different antivirals are available for the treatment of outpatients with COVID-19. Our aim was to describe a real-world experience of outpatient management of COVID-19 subjects at high risk of progression.

METHODS

This prospective observational study conducted in the University Hospital of Pisa (January 2022-July 2022) included consecutive COVID-19 outpatients with at least one risk factor for disease progression. Patients received nirmatrelvir/ritonavir, molnupiravir, or 3-day remdesivir, according to the Italian Medicines Agency (AIFA) indications. All patients were followed up until 30 days from the first positive nasopharyngeal swab. The primary endpoint was a composite of death or hospitalization. Secondary endpoints were occurrence of adverse events and a negative test within 10 days from the first positive test. Multivariable analysis was performed to identify factors associated with death or hospitalization.

RESULTS

Overall, 562 outpatients were included: 114 (20.3%) received molnupiravir, 252 (44.8%) nirmatrelvir/ritonavir, and 196 (34.9%) 3-day remdesivir. The composite endpoint occurred in 2.5% of patients and was more frequent in patients treated with remdesivir (5.1%) compared with molnupiravir (1.8%) or nirmatrelvir/ritonavir (0.8%, ANOVA among groups p = 0.012). On multivariable Cox regression analysis, presence of ≥ 3 comorbidities, hematological disease, gastrointestinal symptoms, and each-day increment from symptoms onset were factors associated with death or hospitalization, while antiviral treatment was not a predictor. Adverse events occurred more frequently in the nirmatrelvir/ritonavir group (49.2%). Nirmatrelvir/ritonavir compared with remdesivir was associated with a higher probability of having a negative test within 10 days from the first positive one.

CONCLUSION

Death or hospitalization did not differ among high-risk COVID-19 outpatients treated with currently available antivirals. Safety and time to a negative test differed among the three drugs.

Assessing the proportion of the Danish population at risk of clinically significant drug-drug interactions with new oral antivirals for early treatment of COVID-19

OBJECTIVES

The oral antiviral drugs nirmatrelvir/ritonavir (NMV/r) and molnupiravir have been approved for early outpatient treatment of COVID-19 to prevent severe disease. Ritonavir, contained in NMV/r, is known to have significant drug-drug interactions (DDI) with several drugs frequently used by the elderly. This communication puts the problem with DDI with oral antiviral COVID-19 treatment into perspective by assessing the percentage of the elderly population at risk of severe COVID-19, using drugs with significant DDI with oral antivirals.

METHODS

We estimated the size of the Danish population at risk of significant DDI with antiviral COVID-19 treatment using the number of claimed prescriptions for drugs predicted to interact with NMV/r in Denmark in 2020.

RESULTS

Danish prescription data demonstrate the extensive use of drugs likely to interact with NMV/r. Anticoagulants contraindicated during NMV/r treatment were used by 20% of people ≥65 years and 30% of people ≥80 years. Statins that must be paused during NMV/r treatment were used by 15-18%. More than one in five used either analgesics, calcium channel blockers, or digoxin.

CONCLUSION

There is major potential for significant DDI with NMV/r in the elderly population at risk of severe COVID-19 disease. This calls for clear guidance for prescribers to ensure patient safety and treatment success.