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Purpose: An oral docetaxel formulation boosted by the Cytochrome P450 (CYP) 3 A inhibitor ritonavir, ModraDoc006/r, is currently under clinical investigation. Based on clinical data, the incidence of grade 1–2 diarrhea is increased with this oral docetaxel formulation compared to the conventional intravenous administration. Loperamide, a frequently used diarrhea inhibitor, could be added to the regimen as symptomatic treatment. However, loperamide is also a substrate of the CYP3A enzyme, which could result in competition between ritonavir and loperamide for this protein. Therefore, we were interested in the impact of coadministered loperamide on the pharmacokinetics of ritonavir-boosted oral docetaxel. Methods: We administered loperamide simultaneously or with an 8-hour delay to humanized CYP3A4 mice (with expression in liver and intestine) receiving oral ritonavir and docetaxel. Concentrations of docetaxel, ritonavir, loperamide and two of its active metabolites were measured. Results: The plasma exposure (AUC and Cmax) of docetaxel was not altered during loperamide treatment, nor were the ritonavir plasma pharmacokinetics. However, the hepatic and intestinal dispositions of ritonavir were somewhat changed in the simultaneous, but not 8-hour loperamide treatment groups, possibly due to loperamide-induced delayed drug absorption. The pharmacokinetics of loperamide itself did not seem to be influenced by ritonavir. Conclusion: These results suggest that delayed loperamide administration can be added to ritonavir-boosted oral docetaxel treatment, without affecting the overall systemic exposure of docetaxel. [ABSTRACT FROM AUTHOR]

Introduction: We compared the effectiveness and virological clearance (VC) at day 7 (T7) post-treatment with molnupiravir, nirmatrelvir/ritonavir, and remdesivir in SARS-CoV-2-infected patients at high risk (HR) for clinical progression. Methods: We conducted a retrospective study enrolling HR patients with mild-to-moderate COVID-19 (Jan–Oct 2022) treated with nirmatrelvir/ritonavir or molnupiravir or 3 days of remdesivir. We investigated clinical recovery at T7 (resolution of symptoms for ≥ 72 h or all-cause death), VC at T7 (PCR/antigenic negative nasopharyngeal swab), and median time to VC (days from symptom onset to the first negative swab). Factors associated with VC were investigated by logistic regression. Results: In the study, 92/376 (43.8%) patients received molnupiravir, 150/376 (24.7%) nirmatrelvir/ritonavir, and 134/376 (31.5%) remdesivir. Forty-nine (13%) patients were unvaccinated or incompletely vaccinated. Patients treated with nirmatrelvir/ritonavir were younger and presented immunodeficiencies more frequently; remdesivir was used more commonly in patients hospitalized for other diseases. A high proportion of patients obtained clinical recovery without differences among the therapies (97.5% for molnupiravir, 98.3% for nirmatrelvir/ritonavir, and 93.6% for remdesivir); 12 (3.7%) patients died. Nirmatrelvir/ritonavir was associated with a higher proportion of T7 VC and a shorter time to VC compared to molnupiravir/remdesivir, also after adjustment for age and immunodeficiency (AOR 0.445 RDV vs. NMV-r, 95% CI 0.240–0.826, p = 0.010; AOR 0.222 MNP vs. NMV-r, 95% CI 0.105–0.472, p < 0.001). Conclusions: SARS-COV-2 antiviral treatments are an excellent therapeutic strategy in HR patients. Nirmatrelvir/ritonavir showed a higher proportion of VC as early as 7 days after treatment, confirming its likely superiority in indirect comparisons. Plain Language Summary: Nirmatrelvir-ritonavir, molnupiravir, and a 3-day course of remdesivir are antiviral therapies recommended in patients with a mild-to-moderate COVID-19 disease at high risk of clinical progression. Randomized controlled trials and observational studies have shown their efficacy in reducing all-cause mortality and clinical progression. Few data are available about a direct comparison among the three drugs; furthermore, the possible role of nirmatrelvir-ritonavir in increasing viral clearance and in reducing the duration of viral shedding needs to be further elucidated. We thus investigated the effectiveness, safety, and virological clearance 7 days after treatment with these three antivirals in our retrospective cohort. We included in the analysis patients that have received these treatments from January 2022 and October 2022; we observed that patients receiving nirmatrelvir-ritonavir displayed a shorter median time from symptoms' onset to virological clearance and a higher proportion of virological clearance at day 7, also after adjustment for possible confounders, compared to molnupiravir and remdesivir. Our data might help in understanding which COVID-19 patients may benefit mostly from antiviral therapies and in the choice of antiviral therapy. [ABSTRACT FROM AUTHOR]

Despite the availability of effective vaccines and treatments for SARS-CoV-2, managing COVID-19 in patients with systemic lupus erythematosus (SLE) remains challenging, particularly considering drug-drug interactions (DDIs). Here, we present a case of DDIs between Tacrolimus (Tac) and nirmatrelvir/ritonavir (NMV/r) in a 32-year-old male with SLE. Following self-administration of NMV/r and resumption of Tac after 5 days, the patient experienced acute nephrotoxicity and neurotoxicity, accompanied by supratherapeutic Tac levels, despite Tac being withheld during NMV/r. The primary cause of this acute toxicity is attributed to ritonavir's inhibitory effect on both CYP3A4 enzymes and P-glycoprotein. Upon admission, Tac was discontinued, and supportive therapies were initiated. Phenytoin, a CYP3A4 inducer, was administered to lower Tac levels under the guidance of clinical pharmacists, effectively alleviating the patient's acute toxic symptoms. The half-life of Tac during the treatment of phenytoin was calculated to be 55.87 h. And no adverse reactions to phenytoin were observed. This case underscores the persistence of enzyme inhibition effects and demonstrates the effectiveness and safety of utilizing CYP3A4 enzyme inducers to mitigate Tac concentrations. Furthermore, it emphasizes the importance of healthcare providers and patients being vigilant about DDIs in Tac recipients. Lastly, it highlights the indispensable role of pharmacist involvement in clinical decision-making and close monitoring in complex clinical scenarios. Although our findings are based on a single case, they align with current knowledge and suggest the potential of individualized combination therapy in managing challenging COVID-19 cases in immunocompromised patients. [ABSTRACT FROM AUTHOR]

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This review comprehensively examines advanced formulation strategies aimed at enhancing the solubility and permeability of ritonavir, an essential antiretroviral medication used in the treatment of HIV/AIDS. Ritonavir's therapeutic efficacy is hindered by its poor aqueous solubility and low oral bioavailability, necessitating innovative approaches to improve its dissolution properties and gastrointestinal absorption. Through an exploration of various techniques, including solid dispersions, nanosuspensions, complexation, lipid-based formulations, micronization, and salt formation, this review highlights the diverse methodologies employed to address these challenges. Each technique is scrutinized for its efficacy in enhancing ritonavir's solubility and permeability, along with considerations regarding feasibility, scalability, and regulatory approval. Furthermore, the review discusses the potential impact of these formulation strategies on the clinical efficacy and patient outcomes of ritonavir therapy, emphasizing the importance of continued research and development in this crucial area of pharmaceutical science. [ABSTRACT FROM AUTHOR]

Background/Aim: Reports regarding the association of remdesivir use for the treatment of Coronavirus disease 2019 (COVID-19) with the development of acute kidney injury (AKI) are inconsistent, and the associations between the use of other antivirals and AKI remain unclear. Therefore, this study investigated whether the use of antiviral drugs for the treatment of COVID-19 is a risk factor for the development of AKI. Patients and Methods: This study analyzed 176,197 reports submitted to the Japanese Adverse Event Reporting Database between 2020 and 2022. Reporting odds ratios (RORs) and 95% confidence intervals (95%CIs) for AKI that were associated with the use of antiviral drugs in patients with COVID-19 were calculated after adjusting for potential confounders. Results: Overall, 5,879 of the reports analyzed were associated with AKI. Signs of AKI were detected with the use of remdesivir [crude ROR (cROR)=2.45; 95%CI=1.91-3.14] and nirmatrelvir/ritonavir (cROR=6.07; 95%CI=4.06-9.06). These results were maintained even after adjusting for potential confounders [remdesivir: adjusted ROR (aROR)=2.18; 95%CI=1.69-2.80, nirmatrelvir/ritonavir: aROR=5.24; 95%CI=3.48-7.90]. However, when analyzing data stratified by reporting year, the association between remdesivir and AKI appeared to diminish over time and was not sustained. Conclusion: Nirmatrelvir/ritonavir use may be associated with developing AKI. This knowledge may be useful in helping patients with COVID-19 avoid AKI complications. [ABSTRACT FROM AUTHOR]

Background: There is an urgent need for therapeutic strategies for inpatients with severe or critical COVID-19. The evaluation of the clinical benefits of nirmatrelvir and ritonavir (Nmr/r) for these patients beyond five days of symptom onset is insufficient. Methods: A new propensity score-matched cohort was constructed by using multicenter data from 6695 adult inpatients with COVID-19 from December 2022 to February 2023 in China after the epidemic control measures were lifted across the country. The severity of disease of the inpatients was based on the tenth trial edition of the Guidelines on the Diagnosis and Treatment of COVID-19 in China. The symptom onset of 1870 enrolled severe or critical inpatients was beyond five days, and they received either Nmr/r plus standard treatment or only standard care. The ratio of patients whose SOFA score improved more than 2 points, crucial respiratory endpoints, changes in inflammatory markers, safety on the seventh day following the initiation of Nmr/r treatment, and length of hospital stay were evaluated. Results: In the Nmr/r group, on Day 7, the number of patients with an improvement in SOFA score ≥ 2 was much greater than that in the standard treatment group (P = 0.024) without a significant decrease in glomerular filtration rate (P = 0.815). Additionally, the rate of new intubation was lower (P = 0.004) and the no intubation days were higher (P = 0.003) in the first 7 days in the Nmr/r group. Other clinical benefits were limited. Conclusions: Our study may provide new insight that inpatients with severe or critical COVID-19 beyond five days of symptom onset benefit from Nmr/r. Future studies, particularly randomized controlled trials, are necessary to verify the above findings. [ABSTRACT FROM AUTHOR]

Within a multistate clinical cohort, SARS-CoV-2 antiviral prescribing patterns were evaluated from April 2022–June 2023 among nonhospitalized patients with SARS-CoV-2 with risk factors for severe COVID-19. Among 3247 adults, only 31.9% were prescribed an antiviral agent (87.6% nirmatrelvir/ritonavir, 11.9% molnupiravir, 0.5% remdesivir), highlighting the need to identify and address treatment barriers. [ABSTRACT FROM AUTHOR]

Currently there is a lack of randomized trial data examining the use of the antiviral nirmatrelvir/ritonavir in paediatric patients with SARS-CoV-2 infection. This target trial emulation study aims to address this gap by evaluating the use of nirmatrelvir/ritonavir in non-hospitalized paediatric patients aged 12–17 years with SARS-CoV-2 Omicron variant infection. Among paediatric patients diagnosed between 16th March 2022 and 5th February 2023, exposure was defined as outpatient nirmatrelvir/ritonavir treatment within 5 days of symptom onset or COVID-19 diagnosis. Primary outcome was 28 day all-cause mortality or all-cause hospitalization, while secondary outcomes were 28 day in-hospital disease progression, 28 day COVID-19-specific hospitalization, multisystem inflammatory syndrome in children (MIS-C), acute liver injury, acute renal failure, and acute respiratory distress syndrome. Overall, 49,378 eligible paediatric patients were included. Nirmatrelvir/ritonavir treatment was associated with reduced 28 day all-cause hospitalization (absolute risk reduction = 0.23%, 95%CI = 0.19%–0.31%; relative risk = 0.66, 95%CI = 0.56–0.71). No events of mortality, in-hospital disease progression, or adverse clinical outcomes were observed among nirmatrelvir/ritonavir users. The findings confirmed the effectiveness of nirmatrelvir/ritonavir in reducing all-cause hospitalization risk among non-hospitalized pediatric patients with SARS-CoV-2 Omicron variant infection. In this target trial emulation study, the authors evaluate effectiveness of nirmatrelvir/ritonavir in non-hospitalized paediatric patients aged 12–17 years with SARS-CoV-2 Omicron infection and show reduced risks of 28 day all-cause mortality or hospitalization associated with the treatment. [ABSTRACT FROM AUTHOR]

The ongoing COVID-19 pandemic continues to pose significant challenges worldwide, despite widespread vaccination. Researchers are actively exploring antiviral treatments to assess their efficacy against emerging virus variants. The aim of the study is to employ M-polynomial, neighborhood M-polynomial approach and QSPR/QSAR analysis to evaluate specific antiviral drugs including Lopinavir, Ritonavir, Arbidol, Thalidomide, Chloroquine, Hydroxychloroquine, Theaflavin and Remdesivir. Utilizing degree-based and neighborhood degree sum-based topological indices on molecular multigraphs reveals insights into the physicochemical properties of these drugs, such as polar surface area, polarizability, surface tension, boiling point, enthalpy of vaporization, flash point, molar refraction and molar volume are crucial in predicting their efficacy against viruses. These properties influence the solubility, permeability, and bio availability of the drugs, which in turn affect their ability to interact with viral targets and inhibit viral replication. In QSPR analysis, molecular multigraphs yield notable correlation coefficients exceeding those from simple graphs: molar refraction (MR) (0.9860), polarizability (P) (0.9861), surface tension (ST) (0.6086), molar volume (MV) (0.9353) using degree-based indices, and flash point (FP) (0.9781), surface tension (ST) (0.7841) using neighborhood degree sum-based indices. QSAR models, constructed through multiple linear regressions (MLR) with a backward elimination approach at a significance level of 0.05, exhibit promising predictive capabilities highlighting the significance of the biological activity I C 50 (Half maximal inhibitory concentration). Notably, the alignment of predicted and observed values for Remdesivir's with obs p I C 50 = 6.01 ,pred p I C 50 = 6.01 ( p I C 50 represents the negative logarithm of I C 50 ) underscores the accuracy of multigraph-based QSAR analysis. The primary objective is to showcase the valuable contribution of multigraphs to QSPR and QSAR analyses, offering crucial insights into molecular structures and antiviral properties. The integration of physicochemical applications enhances our understanding of factors influencing antiviral drug efficacy, essential for combating emerging viral strains effectively. [ABSTRACT FROM AUTHOR]

(1) Background: Geriatric patients are at high risk of complications of Coronavirus disease-2019 (COVID-19) and are good candidates for antiviral drugs. (2) Methods: A retrospective study of electronic health records (EHRs) aiming to describe antiviral (nirmatrelvir and ritonavir (nirmatrelvir/r) or remdesivir) use, drug–drug interactions (DDIs) and adverse drug reactions (ADRs) in elderly patients (75 and over), hospitalized with mild-to-moderate COVID-19 between July 2022 and June 2023. (3) Results: Out of 491 patients (mean age: 86.9 years), 180 (36.7%) received nirmatrelvir/r, 78 (15.9%) received remdesivir, and 233 (47.4%) received no antiviral therapy. No association was found between the choice of antiviral and the demographic or medical data. No serious ADR was observed. Nirmatrelvir/r dosage adjustment was inadequate in 65% of patients with renal impairment. In total, 128 patients (71%) on nirmatrelvir/r had potential pharmacokinetic DDIs, with 43 resulting in a possibly related ADR. In the remdesivir group, pharmacodynamic DDIs were more frequent, with QTc prolongation risk in 56 patients (72%). Only 20 patients underwent follow-up ECG, revealing QTc prolongation in 4. (4) Conclusions: There is an underutilization of antivirals despite their justified indications. Nirmatrelvir/r dosage was rarely adjusted to renal function. Dose adjustments and closer monitoring are needed due to the high risk of drug interactions. [ABSTRACT FROM AUTHOR]

Drug-Combination Nanoparticles (DcNP) are a novel drug delivery system designed for synchronized delivery of multiple drugs in a single, long-acting, and targeted dose. Unlike depot formulations, slowly releasing drug at the injection site into the blood, DcNP allows multiple-drug-in-combination to collectively distribute from the injection site into the lymphatic system. Two distinct classes of long-acting injectables products are proposed based on pharmacokinetic mechanisms. Class I involves sustained release at the injection site. Class II involves a drug-carrier complex composed of lopinavir, ritonavir, and tenofovir uptake and retention in the lymphatic system before systemic access as a part of the PBPK model validation. For clinical development, Class II long-acting drug-combination products, we leverage data from 3 nonhuman primate studies consisting of nine PK datasets: Study 1, varying fixed-dose ratios; Study 2, short multiple dosing with kinetic tails; Study 3, long multiple dosing (chronic). PBPK validation criteria were established to validate each scenario for all drugs. The models passed validation in 8 of 9 cases, specifically to predict Study 1 and 2, including PK tails, with ritonavir and tenofovir, fully passing Study 3 as well. PBPK model for lopinavir in Study 3 did not pass the validation due to an observable time-varying and delayed drug accumulation, which likely was due to ritonavir's CYP3A inhibitory effect building up during multiple dosing that triggered a mechanism-based drug-drug interaction (DDI). Subsequently, the final model enables us to account for this DDI scenario. [ABSTRACT FROM AUTHOR]

Since the first discovery of the first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in December 2019 in Wuhan, China, the virus quickly spread throughout the world and became a pandemic. The virus has continued to pose challenges, with new variants emerging and evolving, necessitating ongoing adaptation and response from governments, healthcare systems, and communities worldwide. Various drug regimens were introduced with immediate implementation and there is a need for the study of Review of Quality Control aspects of drugs employed in COVID-19 treatment is critical for ensuring their safety, efficacy, and reliability. With the proliferation of pharmaceutical interventions aimed at combating the pandemic, such as antiviral, immunomodulators, and repurposed medications, a thorough review is essential. Harnessing immune modulators, monoclonal antibodies, and antiviral agents like the ritonavir (RTN)/nirmatrelvir (NTV) combination, molnupiravir (MLP), and favipiravir (FVP) presents a multifaceted approach to combating COVID-19. These pharmaceutical interventions offer diverse mechanisms of action aimed at suppressing viral replication, mitigating immune responses, and enhancing the body's ability to combat the virus Improving analytical methods to achieve precise and sensitive quantification of these drugs is paramount for advancing quality control measures. The study delved into a variety of analytical techniques for assessing the concentrations of antiviral drugs utilized in COVID-19 treatment. The techniques covered by these methods include Ultra High-Performance Liquid Chromatography (UHPLC-MS/MS) or Ultraviolet detectors (HPLC-UV), High-Performance Thin Layer Chromatography (HPTLC), Reversed Phase-High Performance Liquid Chromatography (RP-HPLC), High-Performance Liquid Chromatography Tandem Mass Spectrometry (HPLCMS/MS) or Ultraviolet detectors (TLC-UV), and Micellar Liquid Chromatography (MLC). With regard to sensitivity, selectivity, and efficiency in measuring drug concentrations, each of these methods has special benefits. The TLC and HPTLC techniques offer reasonably easy sample preparation at a reasonable price, whereas the RP-HPLC, HPLC-MS/MS, UHPLC-MS/MS, and UPLC-UV techniques offer more sensitivity and precision, especially in complex sample types. Furthermore, precise identification and quantification of pharmacological molecules at low concentrations are made possible by the application of UV and mass spectrometric detection. The purpose of the study is to assess the effectiveness of the RP-HPLC method and validate the chosen medications. The results of the study will be further examined, and the development of a novel RP-HPLC method will be optimized. These analytical techniques can be refined to satisfy legal specifications and guarantee accurate anti-COVID-19 medication quantification. Here, we focus on clarifying modern, straightforward, fast, accurate, and eco-friendly analytical techniques that demonstrate great sensitivity, selectivity, and accuracy for the analysis of anti-COVID-19 medications. [ABSTRACT FROM AUTHOR]

Introduction: The COVID‐19 pandemic has taken many forms and continues to evolve, now around the Omicron wave, raising concerns over the globe. With COVID‐19 being declared no longer a "public health emergency of international concern (PHEIC)," the COVID pandemic is still far from over, as new Omicron subvariants of interest and concern have risen since January of 2023. Mainly with the XBB.1.5 and XBB.1.16 subvariants, the pandemic is still very much "alive" and "breathing." Methods: This review consists of five highly concerning questions about the current state of the COVID Omicron peak. We searched four main online databases to answer the first four questions. For the last one, we performed a systematic review of the literature, with keywords "Omicron," "Guidelines," and "Recommendations." Results: A total of 31 articles were included. The main symptoms of the current Omicron wave include a characteristically high fever, coughing, conjunctivitis (with itching eyes), sore throat, runny nose, congestion, fatigue, body ache, and headache. The median incubation period of the symptoms is shorter than the previous peaks. Vaccination against COVID can still be considered effective for the new subvariants. Conclusion: Guidelines recommend continuation of personal protective measures, third and fourth dose boosters, along with administration of bivalent messenger RNA vaccine boosters. The consensus antiviral treatment is combination therapy using Nirmatrelvir and Ritonavir, and the consensus for pre‐exposure prophylaxis is Tixagevimab and Cilgavimab combination. We hope the present paper raises awareness for the continuing presence of COVID and ways to lower the risks, especially for at‐risk groups. Key points: The COVID pandemic is far from over, with new variants of interest and concern rising since January of 2023 (mainly XBB.1.5 and XBB.1.16 subvariants).The main symptoms of the current Omicron wave include a high fever, coughing, conjunctivitis (with itching of the eyes), sore throat, runny nose and congestion, fatigue, body ache, and headache.The median incubation period for the current peak was calculated to be 3.8 days which is shorter than the incubation period calculated for most of the previous peaks; and the median duration of the symptoms was calculated to be 5 days for the current peak which is shorter than the duration calculated for the previous peaks by 3–5 days.A cumulative 64.42% of the population worldwide are fully vaccinated against COVID‐19 as of June 16, 2023. Vaccination against COVID can still be considered mostly effective against new symptoms, severe disease, long COVID, and death for the new subvariants.Guidelines recommend continuation of personal protective measures, third and fourth dose boosters, particularly in individuals above 60, immunocompromised patients, and healthcare personnel, along with administration of bivalent messenger RNA vaccine boosters.The consensus option for antiviral treatment is combination therapy using Nirmatrelvir and Ritonavir, and the consensus for pre‐exposure prophylaxis is Tixagevimab and Cilgavimab combination. [ABSTRACT FROM AUTHOR]

Background and objectives: Nirmatrelvir/ritonavir was administered orally to manage mild to moderate symptoms of COVID-19 in adult patients. The objectives of this study were to (i) evaluate the cost-effectiveness of prescribing nirmatrelvir/ritonavir within 5 days of a COVID-19 illness in order to avert hospitalization within a 30-day period in the Malaysia setting; (ii) determine how variations in pricing and hospitalization rates will affect the cost-effectiveness of nirmatrelvir/ritonavir. Methods: The 30-day hospitalization related to COVID-19 was determined using 1 to 1 propensity score-matched real-world data in Malaysia from 14 July 2022 to 14 November 2022. To determine the total per-person costs related to COVID-19, we added the cost of drug (nirmatrelvir/ritonavir or control), clinic visits and inpatient care. Incremental cost-effectiveness ratio (ICER) per hospitalization averted was calculated. Results: Our cohort included 31,487 patients. The rate of hospitalization within 30 days was found to be 0.35% for the group treated with nirmatrelvir/ritonavir, and 0.52% for the control group. The nirmatrelvir/ritonavir group cost an additional MYR 1,625.72 (USD 358.88) per patient. This treatment also resulted in a reduction of 0.17% risk for hospitalization, which corresponded to an ICER of MYR 946,801.26 (USD 209,006.90) per hospitalization averted. Conclusion: In Malaysia, where vaccination rates were high, nirmatrelvir/ritonavir has been shown to be beneficial in the outpatient treatment of adults with COVID-19 who have risk factors; however, it was only marginally cost effective against hospitalization for healthy adults during the Omicron period. [ABSTRACT FROM AUTHOR]

This article explores the challenges faced by cystic fibrosis (CF) patients in low- to middle-income countries in accessing the triple combination therapy of elexacaftor, tezacaftor, and ivacaftor (ETI). The therapy is currently expensive and not widely available due to regulatory approval and cost issues. The authors propose a strategy using pharmacokinetic enhancement to reduce the cost of treatment, which involves the use of boosting agents like ritonavir. They also suggest the potential use of generic ETI formulations. Preliminary data from South Africa shows promising results, but further clinical trials are needed to evaluate the effectiveness, safety, and cost-effectiveness of this approach. [Extracted from the article]

BackgroundIn the USA, oral nirmatrelvir-ritonavir is authorised for use in patients aged 12 years or older with mild-to-moderate COVID-19 who are at risk of progression to severe disease and hospitalisation. We aimed to establish the effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions and death in people with COVID-19 in an outpatient prescribing context in the USA.MethodsIn this matched observational outpatient cohort study in the Kaiser Permanente Southern California (CA, USA) health-care system, data were extracted from electronic health records of non-hospitalised patients aged 12 years or older who received a positive SARS-CoV-2 PCR test result (their index test) between April 8 and Oct 7, 2022, and had not received another positive test result within the preceding 90 days. We compared outcomes between people who received nirmatrelvir-ritonavir and those who did not receive nirmatrelvir-ritonavir by matching cases by date, age, sex, clinical status (including care received, the presence or absence of acute COVID-19 symptoms at testing, and time from symptom onset to testing), vaccination history, comorbidities, health-care seeking during the previous year, and BMI. Our primary endpoint was the estimated effectiveness of nirmatrelvir-ritonavir in preventing hospital admissions or death within 30 days of a positive test for SARS-CoV-2.Findings7274 nirmatrelvir-ritonavir recipients and 126 152 non-recipients with positive SARS-CoV-2 tests were included in our study. 5472 (75·2%) treatment recipients and 84 657 (67·1%) non-recipients were tested within 5 days of symptom onset. Nirmatrelvir-ritonavir had an overall estimated effectiveness of 53·6% (95% CI 6·6-77·0) in preventing hospital admission or death within 30 days of a positive test for SARS-CoV-2, which increased to 79·6% (33·9-93·8) when nirmatrelvir-ritonavir was dispensed within 5 days of symptom onset. Within the subgroup of patients tested within 5 days of symptom onset and whose treatment was dispensed on the day of their test, the estimated effectiveness of nirmatrelvir-ritonavir was 89·6% (50·2-97·8).InterpretationIn a setting with high levels of COVID-19 vaccine uptake, nirmatrelvir-ritonavir effectively reduced the risk of hospital admission or death within 30 days of a positive outpatient SARS-CoV-2 test.FundingUS Centers for Disease Control and Prevention and US National Institutes of Health.

BackgroundInformation about the effectiveness of oral antivirals in preventing short- and long-term COVID-19-related outcomes in the setting of Omicron variant transmission and COVID-19 vaccination is limited.ObjectiveTo measure the effectiveness of nirmatrelvir-ritonavir and molnupiravir for outpatient treatment of COVID-19.DesignThree retrospective target trial emulation studies comparing matched cohorts of nirmatrelvir-ritonavir versus no treatment, molnupiravir versus no treatment, and nirmatrelvir-ritonavir versus molnupiravir.SettingVeterans Health Administration (VHA).ParticipantsNonhospitalized veterans in VHA care who were at risk for severe COVID-19 and tested positive for SARS-CoV-2 during January through July 2022.InterventionNirmatrelvir-ritonavir or molnupiravir pharmacotherapy.MeasurementsIncidence of any hospitalization or all-cause mortality at 30 days and from 31 to 180 days.ResultsEighty-seven percent of participants were male; the median age was 66 years, and 18% were unvaccinated. Compared with matched untreated control participants, those treated with nirmatrelvir-ritonavir (n = 9607) had lower 30-day risk for hospitalization (22.07 vs. 30.32 per 1000 participants; risk difference [RD], -8.25 [95% CI, -12.27 to -4.23] per 1000 participants) and death (1.25 vs. 5.47 per 1000 participants; RD, -4.22 [CI, -5.45 to -3.00] per 1000 participants). Among persons alive at day 31, reductions were seen in 31- to 180-day incidence of death (hazard ratio, 0.66 [CI, 0.49 to 0.89]) but not hospitalization (subhazard ratio, 0.90 [CI, 0.79 to 1.02]). Molnupiravir-treated participants (n = 3504) had lower 30-day and 31- to 180-day risks for death (3.14 vs. 13.56 per 1000 participants at 30 days; RD, -10.42 [CI, -13.49 to -7.35] per 1000 participants; hazard ratio at 31 to 180 days, 0.67 [CI, 0.48 to 0.95]) but not hospitalization. A difference in 30-day or 31- to 180-day risk for hospitalization or death was not observed between matched nirmatrelvir- or molnupiravir-treated participants.LimitationThe date of COVID-19 symptom onset for most veterans was unknown.ConclusionNirmatrelvir-ritonavir was effective in reducing 30-day hospitalization and death. Molnupiravir was associated with a benefit for 30-day mortality but not hospitalization. Further reductions in mortality from 31 to 180 days were observed with both antivirals.Primary funding sourceU.S. Department of Veterans Affairs.

In this current research, we conceptualized a novel nanotechnology-enabled synthesis approach of targeting HIV-harboring tissues via second-generation (G2) polyamidoamine (PAMAM) mannosylated (MPG2) dendrimers for programmed delivery of anti-HIV drugs efavirenz (EFV) and ritonavir (RTV). Briefly, here mannose served purpose of ligand in this EFV and RTV-loaded PAMAM G2 dendrimers, synthesized by divergent techniques, denoted as MPG2ER. The developed nanocarriers were characterized by different analytical tools FTIR, NMR, zeta potential, particle size, and surface morphology. The results of confocal microscopy showed substantial alterations in the morphology of H9 cells, favored by relatively higher drug uptake through the MPG2ER. Interestingly, the drug uptake study and cytotoxicity assay of MPG2ER demonstrated that it showed no significant toxicity up to 12.5 µM. A typical flow cytometry histogram also revealed that MPG2ER efficiently internalized both drugs, with an increase in drug uptake of up to 81.2 %. It also enhanced the plasma pharmacokinetics of EFV, with Cmax7.68 μg/ml, AUC of 149.19 (μg/ml) * hr, and MRT of 26.87 hrs. Subsequently, tissue pharmacokinetics further evidence that MPG2ER accumulated more in distant Human immunodeficiency virus (HIV) reservoir tissues, such as the lymph nodes and spleen, but without exhibiting significant toxicity. Abovementioned compelling evidences strongly favored translational roles of MPG2 as a potential therapeutic strategy in the clinical eradication of HIV from viral reservoir tissue.

Background: According to the Evaluation of Protease Inhibition for COVID-19 in High-Risk Patients (EPIC-HR) study, compared with a placebo, nirmatrelvir/ritonavir significantly reduced the risk of coronavirus disease 2019 (COVID-19)-related hospitalization or mortality in unvaccinated patients. The Delta variant was the most prevalent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant among all treatment recipients in the EPIC-HR study. The Omicron variant is less pathogenic than the Delta variant. The efficacy of nirmatrelvir/ritonavir in partially or fully immunized patients with Omicron variant-related infections must be further evaluated. Objectives: The current meta-analysis aimed to evaluate the therapeutic efficacy of nirmatrelvir/ritonavir based on factors including hospitalization, all-cause mortality, and COVID-19 rebound in patients who were partially or fully immunized against COVID-19. Methods: This meta-analysis aimed to evaluate the therapeutic efficacy of nirmatrelvir/ritonavir based on factors including hospitalization, all-cause mortality, and COVID-19 rebound in patients who were partially or fully immunized against COVID-19. It included 26 studies that directly examined the clinical efficacy of nirmatrelvir/ritonavir versus placebo in adult patients with SARS-CoV-2 infection caused by the Omicron variant. The search criteria comprised keywords such as hospitalization, all-cause mortality, and COVID-19 rebound. Results: The all-cause mortality risk was reduced by 59% in patients aged ≥65 years. However, their hospitalization risk decreased by only 36%. The reduction in all-cause mortality and hospitalization risk was similar between patients with low and high COVID-19 vaccination coverage. Patients receiving nirmatrelvir/ritonavir had a higher incidence of COVID-19 rebound than those receiving a placebo. However, the hospitalization risk and all-cause mortality of adult patients with COVID-19 treated with nirmatrelvir/ritonavir reduced by 53% and 57%, respectively. Conclusion: The current meta-analysis of 26 studies indicates that adult patients with COVID-19 treated with nirmatrelvir/ritonavir reduced the risk of hospitalization by 53% and all-cause mortality by 57% compared to a placebo.

The article discusses a study by G. C. K. Chan and colleagues which evaluated nirmatrelvir-ritonavir (NMV/r) treatment among patients with mild COVID-19 and advanced chronic kidney disease (CKD). The researchers showed that a modified dose of NMV/r suppressed the severe acute respiratory syndrome 2 (SARS-CoV-2) viral load with a favorable safety profile. Also mentioned are how diagnosis was made, the assessment of NMV/r plasma concentration, and implication of high free fraction level of NMV.

This document summarizes a study on the treatment of SARS-CoV-2 infection in patients with lymphoproliferative disorders. The study found that combination treatments, such as sotrovimab plus one antiviral agent, were used in three patients, but two of them did not clear the infection. The most commonly used regimen was a combination of nirmatrelvir/ritonavir plus remdesivir. The study highlights the lack of standardized management for these patients and the need for further research on the optimal treatment for SARS-CoV-2 in individuals with lymphoproliferative malignancies. The authors recommend a pragmatic approach of using a combination of at least two drugs until the infection is eradicated. [Extracted from the article]

Nirmatrelvir-ritonavir (Paxlovid) is recommended to reduce the risk of hospitalization from coronavirus disease 2019 (COVID-19) in pregnancy. Data on use in pregnancy, including prescribing patterns and patient experience (adverse effects, incidence of rebound), are limited. We performed a cross-sectional study in which we surveyed a cohort of vaccinated pregnant or lactating individuals with breakthrough COVID-19. Of 35 pregnant respondents, 51.4% were prescribed and 34.3% took nirmatrelvir-ritonavir; of these, 91.7% experienced dysgeusia and 50.0% had rebound (50.0% positive test result, 33.3% return of symptoms). Three of five lactating respondents were prescribed and two took nirmatrelvir-ritonavir. There were no significant adverse outcomes. Unknown risk was the most common reason for declining nirmatrelvir-ritonavir. More research is needed to establish the safety of nirmatrelvir-ritonavir in pregnancy and lactation, to improve public health messaging, and to increase uptake of this treatment.

BackgroundAlthough super-boosted lopinavir/ritonavir (LPV/r; ratio 4:4 instead of 4:1) is recommended for infants living with HIV and receiving concomitant rifampicin, in clinical practice, many different LPV/r dosing strategies are applied due to poor availability of pediatric separate ritonavir formulations needed to superboost. We evaluated LPV pharmacokinetics in infants with HIV receiving LPV/r dosed according to local guidelines in various sub-Saharan African countries with or without rifampicin-based tuberculosis (TB) treatment.MethodsThis was a 2-arm pharmacokinetic substudy nested within the EMPIRICAL trial (#NCT03915366). Infants aged 1-12 months recruited into the main study were administered LPV/r according to local guidelines and drug availability either with or without rifampicin-based TB treatment; during rifampicin cotreatment, they received double-dosed (ratio 8:2) or semisuperboosted LPV/r (adding a ritonavir 100 mg crushed tablet to the evening LPV/r dose). Six blood samples were taken over 12 hours after intake of LPV/r.ResultsIn total, 14/16 included infants had evaluable pharmacokinetic curves; 9/14 had rifampicin cotreatment (5 received double-dosed and 4 semisuperboosted LPV/r). The median (IQR) age was 6.4 months (5.4-9.8), weight 6.0 kg (5.2-6.8), and 10/14 were male. Of those receiving rifampicin, 6/9 infants (67%) had LPV Ctrough

The factors contributing to the rapid emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) BA.4 and BA.5 subvariants in populations that experienced recent surges of BA.2 and BA.2.12.1 infections are not understood. Neutralizing antibodies (NAbs) are likely to protect against severe disease if present in sufficient quantity. We found that after BA.2 or BA.2.12.1 infection, NAb responses were largely cross-neutralizing but were much less effective against BA.5. In addition, individuals who were infected and treated early with nirmatrelvir/ritonavir (Paxlovid) had lower NAb levels than untreated individuals.

The Precision Interventions for Severe and/or Exacerbation-Prone Asthma clinical trials network is actively assessing novel treatments for severe asthma during the coronavirus disease (COVID-19) pandemic and has needed to adapt to various clinical dilemmas posed by the COVID-19 pandemic. Pharmacologic interactions between established asthma therapies and novel drug interventions for COVID-19 infection, including antivirals, biologics, and vaccines, have emerged as a critical and unanticipated issue in the clinical care of asthma. In particular, impaired metabolism of some long-acting beta-2 agonists by the cytochrome P4503A4 enzyme in the setting of antiviral treatment using ritonavir-boosted nirmatrelvir (NVM/r, brand name Paxlovid) may increase risk for adverse cardiovascular events. Although available data have documented the potential for such interactions, these issues are largely unappreciated by clinicians who treat asthma, or those dispensing COVID-19 interventions in patients who happen to have asthma. Because these drug-drug interactions have not previously been relevant to patient care, clinicians have had no guidance on management strategies to reduce potentially serious interactions between treatments for asthma and COVID-19. The Precision Interventions for Severe and/or Exacerbation-Prone Asthma network considered the available literature and product information, and herein share our considerations and plans for treating asthma within the context of these novel COVID-19-related therapies.

Artemisinin-based combination therapies (ACTs) are the primary treatment for malaria. It is essential to characterize the pharmacokinetics (PKs) and pharmacodynamics (PDs) of ACTs in vulnerable populations at risk of suboptimal dosing. We developed a population PK/PD model using data from our previous study of artemether-lumefantrine in HIV-uninfected and HIV-infected children living in a high-transmission region of Uganda. HIV-infected children were on efavirenz-, nevirapine-, or lopinavir-ritonavir-based antiretroviral regimens, with daily trimethoprim-sulfamethoxazole prophylaxis. We assessed selection for resistance in two key parasite transporters, pfcrt and pfmdr1, over 42-day follow-up and incorporated genotyping into a time-to-event model to ascertain how resistance genotype in relation to drug exposure impacts recurrence risk. Two hundred seventy-seven children contributed 364 episodes to the model (186 HIV-uninfected and 178 HIV-infected), with recurrent microscopy-detectable parasitemia detected in 176 episodes by day 42. The final model was a two-compartment model with first-order absorption and an estimated age effect on bioavailability. Systemic lumefantrine exposure was highest with lopinavir-ritonavir, lowest with efavirenz, and equivalent with nevirapine and HIV-uninfected children. HIV status and lumefantrine concentration were significant factors associated with recurrence risk. Significant selection was demonstrated for pfmdr1 N86 and pfcrt K76 in recurrent infections, with no evidence of selection for pfmdr1 Y184F. Less sensitive parasites were able to tolerate lumefantrine concentrations ~ 3.5-fold higher than more sensitive parasites. This is the first population PK model of lumefantrine in HIV-infected children and demonstrates selection for reduced lumefantrine susceptibility, a concern as we confront the threat to ACTs posed by emerging artemisinin resistance in Africa.

Abstract 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.

We isolated a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) BA.2 variant from a person with coronavirus disease 2019 recrudescence after nirmatrelvir/ritonavir treatment. Antiviral sensitivity and neutralizing antibody testing were performed with both parental SARS-CoV-2 and multiple variants of concern. We found that neither nirmatrelvir resistance nor absence of neutralizing immunity was a likely cause of the recrudescence.

IntroductionOral administration of ritonavir-boosted nirmatrelvir (Paxlovid) was found to be promising in the treatment of coronavirus disease 2019. The active antiviral component nirmatrelvir in Paxlovid is co-formulated with ritonavir, a strong cytochrome P450 (CYP) 3A4 inhibitor. Many oral targeted therapies indicated for lung cancer are known substrates of CYP 3A4, and concurrent use with Paxlovid may lead to potential drug-drug interaction (DDI). The purpose of this review is to evaluate the potential DDI between targeted therapies and supportive care for lung cancer and ritonavir-boosted nirmatrelvir.MethodsDrug database search in PubMed and the Food and Drug Administration was conducted to identify pharmacokinetic data on oral tyrosine kinase inhibitors (TKIs) used in NSCLC, both Food and Drug Administration approved and those in development. Metabolism pathways for various TKIs are extracted, and the impact of TKI area under the curves and maximum concentration by strong CYP 3A4 inducers and inhibitors is summarized. The most common toxicities and supportive care medications for the TKI were identified.ResultsAmong EGFR and exon 20 insertion inhibitors, afatinib is least likely to be affected by CYP 3A4, followed by dacomitinib and osimertinib. Among ALK inhibitors, alectinib is the least susceptible to CYP 3A4. ROS1 inhibitors are affected by CYP 3A4 inhibition with the exception of crizotinib. Among MET inhibitors, capmatinib is substantially affected by CYP 3A4 inhibition. Drug exposure of RET inhibitors is expected to increase with CYP 3A4 inhibition, with selpercatinib being the least affected. Certain supportive care medications for lung cancer TKI may have relevant DDIs.ConclusionsThe clinical impact of the DDI between lung cancer TKI and ritonavir-boosted nirmatrelvir varies largely on the basis of the susceptibility of CYP 3A4 inhibition caused by the antiviral. Close monitoring and medication adjustments (i.e., dose changes or alternative coronavirus disease 2019 therapy) can be used to overcome DDI to ensure patient safety.