Clinical efficacy of nirmatrelvir and ritonavir combination for treating diabetic patients with COVID-19.

The aim of this study was to investigate the clinical efficacy of a combination of nirmatrelvir and ritonavir (NMV-r) for treating COVID-19 in patients with diabetes mellitus (DM). This retrospective cohort study used the TriNetX research network to identify adult diabetic patients with COVID-19 between January 1, 2020, and December 31, 2022. Propensity score matching was used to match patients who received NMV-r (NMV-r group) with those who did not receive NMV-r (control group). The primary outcome was all-cause hospitalization or death during the 30-day follow-up period. Two cohorts comprising 13 822 patients with balanced baseline characteristics were created using propensity score matching. During the follow-up period, the NMV-r group had a lower risk of all-cause hospitalization or death than the control group (1.4% [n = 193] vs. 3.1% [n = 434]; hazard ratio [HR], 0.497; 95% confidence interval [CI], 0.420-0.589). Compared with the control group, the NMV-r group also had a lower risk of all-cause hospitalization (HR, 0.606; 95% CI, 0.508-0.723) and all-cause mortality (HR, 0.076; 95% CI, 0.033-0.175). This lower risk was consistently observed in almost all subgroup analyses, which examined sex (male: 0.520 [0.401-0.675]; female: 0.586 [0.465-0.739]), age (age 18-64 years: 0.767 [0.601-0.980]; ≥65 years: 0.394 [0.308-0.505]), level of HbA1c (<7.5%: 0.490 [0.401-0.599]; ≥7.5%: 0.655 [0.441-0.972]), unvaccinated (0.466 [0.362-0.599]), type 1 DM (0.453 [0.286-0.718]) and type 2 DM (0.430 [0.361-0.511]). NMV-r can help reduce the risk of all-cause hospitalization or death in nonhospitalized patients with DM and COVID-19.

A mathematical model of SARS-CoV-2 immunity predicts paxlovid rebound.

Nirmatrelvir/ritonavir (Paxlovid), an oral antiviral medication targeting SARS-CoV-2, remains an important treatment for COVID-19. Initial studies of nirmatrelvir/ritonavir were performed in SARS-CoV-2 unvaccinated patients without prior confirmed SARS-CoV-2 infection; however, most individuals have now either been vaccinated and/or have experienced SARS-CoV-2 infection. After nirmatrelvir/ritonavir became widely available, reports surfaced of "Paxlovid rebound," a phenomenon in which symptoms (and SARS-CoV-2 test positivity) would initially resolve, but after finishing treatment, symptoms and test positivity would return. We used a previously described parsimonious mathematical model of immunity to SARS-CoV-2 infection to model the effect of nirmatrelvir/ritonavir treatment in unvaccinated and vaccinated patients. Model simulations show that viral rebound after treatment occurs only in vaccinated patients, while unvaccinated (SARS-COV-2 naïve) patients treated with nirmatrelvir/ritonavir do not experience any rebound in viral load. This work suggests that an approach combining parsimonious models of the immune system could be used to gain important insights in the context of emerging pathogens.

High-titer convalescent plasma plus nirmatrelvir/ritonavir treatment for non-resolving COVID-19 in six immunocompromised patients.

OBJECTIVES: Immunocompromised patients have an increased risk of severe or prolonged COVID-19. Currently available drugs are registered to treat COVID-19 during the first 5 to 7 days after symptom onset. Data on the effectivity in immunocompromised patients with chronic non-resolving COVID-19 are urgently needed. Here, we report the outcome of patients treated with nirmatrelvir/ritonavir together with high-titer convalescent plasma (CP) in six immunocompromised patients with non-resolving COVID-19. METHODS: Immunocompromised patients with persisting COVID-19 (positive PCR with Ct values <30 for ≥20 days) received off-label therapy with nirmatrelvir/ritonavir. It was combined with CP containing BA.5 neutralizing titers of ≥1/640 whenever available. Follow-up was done by PCR and sequencing on nasopharyngeal swabs on a weekly basis until viral genome was undetectable consecutively. RESULTS: Five immunocompromised patients were treated with high-titer CP and 5 days of nirmatrelvir/ritonavir. One patient received nirmatrelvir/ritonavir monotherapy. Median duration of SARS-CoV-2 PCR positivity was 70 (range 20-231) days before nirmatrelvir/ritonavir treatment. In four patients receiving combination therapy, no viral genome of SARS-CoV-2 was detected on day 7 and 14 after treatment while the patient receiving nirmatrelvir/ritonavir monotherapy, the day 7 Ct value increased to 34 and viral genome was undetectable thereafter. Treatment was unsuccessful in one patient. In this patient, sequencing after nirmatrelvir/ritonavir treatment did not show protease gene mutations. CONCLUSIONS: In immunocompromised patients with non-resolving COVID-19, the combination of nirmatrelvir/ritonavir and CP may be an effective treatment. Larger prospective studies are needed to confirm these preliminary results and should compare different treatment durations.

Non-randomized evaluation of hospitalization after a prescription for nirmatrelvir/ritonavir versus molnupiravir in high-risk COVID-19 outpatients.

OBJECTIVES: To assess and compare subsequent hospital admissions within 30 days for patients after receiving a prescription for either oral nirmatrelvir/ritonavir or oral molnupiravir. METHODS: We conducted a retrospective review of 3207 high-risk, non-hospitalized adult COVID-19 patients who received a prescription for molnupiravir (n = 209) or nirmatrelvir/ritonavir (n = 2998) at an academic medical centre in New York City from April to December 2022. Variables including age, vaccination status, high-risk conditions and demographic factors were pulled from the electronic medical record. We used multivariable logistic regression to adjust for potential confounding variables. RESULTS: All-cause 30 day hospitalization was not significantly different between patients who received nirmatrelvir/ritonavir compared with molnupiravir (1.4% versus 1.9%, P value = 0.55). The association between COVID-related hospitalization and medication was also not significant (0.7%versus 0.5%, P value = 0.99). Patients who received molnupiravir were more likely to have more underlying high-risk conditions. After adjusting for potential confounders, the odds of all-cause hospitalizations were not significantly different between patients who received nirmatrelvir/ritonavir compared with molnupiravir (OR = 1.16, 95% CI: 0.4-3.3, P value = 0.79). CONCLUSIONS: These data provide additional evidence to support molnupiravir as a suitable alternative when other COVID-19 antivirals cannot be given.

[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.

Effectiveness of COVID-19 Treatment With Nirmatrelvir-Ritonavir or Molnupiravir Among U.S. Veterans: Target Trial Emulation Studies With One-Month and Six-Month Outcomes.

BACKGROUND: Information 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. OBJECTIVE: To measure the effectiveness of nirmatrelvir-ritonavir and molnupiravir for outpatient treatment of COVID-19. DESIGN: Three retrospective target trial emulation studies comparing matched cohorts of nirmatrelvir-ritonavir versus no treatment, molnupiravir versus no treatment, and nirmatrelvir-ritonavir versus molnupiravir. SETTING: Veterans Health Administration (VHA). PARTICIPANTS: Nonhospitalized veterans in VHA care who were at risk for severe COVID-19 and tested positive for SARS-CoV-2 during January through July 2022. INTERVENTION: Nirmatrelvir-ritonavir or molnupiravir pharmacotherapy. MEASUREMENTS: Incidence of any hospitalization or all-cause mortality at 30 days and from 31 to 180 days. RESULTS: Eighty-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. LIMITATION: The date of COVID-19 symptom onset for most veterans was unknown. CONCLUSION: Nirmatrelvir-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 SOURCE: U.S. Department of Veterans Affairs.

Analysis of All-Cause Hospitalization and Death Among Nonhospitalized Patients With Type 2 Diabetes and SARS-CoV-2 Infection Treated With Molnupiravir or Nirmatrelvir-Ritonavir During the Omicron Wave in Hong Kong.

Importance: Diabetes and COVID-19 are both global pandemics, and type 2 diabetes is a common comorbidity in patients with acute COVID-19 and is proven to be a key determinant of COVID-19 prognosis. Molnupiravir and nirmatrelvir-ritonavir are oral antiviral medications recently approved for nonhospitalized patients with mild to moderate COVID-19, following demonstration of their efficacies in reducing adverse outcomes of the disease; it is crucial to clarify whether both oral antiviral medications are efficacious in a population consisting exclusively of patients with type 2 diabetes. Objective: To evaluate the effectiveness of molnupiravir and nirmatrelvir-ritonavir in a contemporary population-based cohort comprising exclusively nonhospitalized patients with type 2 diabetes and SARS-CoV-2 infection. Design, Setting, and Participants: This retrospective cohort study was performed using population-based electronic medical record data for patients in Hong Kong with type 2 diabetes and confirmed SARS-CoV-2 infection between February 26 and October 23, 2022. Each patient was followed up until death, outcome event, crossover of oral antiviral treatment, or end of the observational period (October 30, 2022), whichever came first. Outpatient oral antiviral users were divided into molnupiravir and nirmatrelvir-ritonavir treatment groups, respectively, and nontreated control participants were matched through 1:1 propensity score matching. Data analysis was performed on March 22, 2023. Exposures: Molnupiravir (800 mg twice daily for 5 days) or nirmatrelvir-ritonavir (300 mg nirmatrelvir and 100 mg ritonavir twice daily for 5 days, or 150 mg nirmatrelvir and 100 mg ritonavir for patients with an estimated glomerular filtration rate of 30-59 mL/min per 1.73 m2). Main Outcomes and Measures: The primary outcome was a composite of all-cause mortality and/or hospitalization. The secondary outcome was in-hospital disease progression. Hazard ratios (HRs) were estimated with Cox regression. Results: This study identified 22 098 patients with type 2 diabetes and COVID-19. A total of 3390 patients received molnupiravir and 2877 received nirmatrelvir-ritonavir in the community setting. After application of exclusion criteria followed by 1:1 propensity score matching, this study comprised 2 groups. One group included 921 molnupiravir users (487 men [52.9%]), with a mean (SD) age of 76.7 (10.8) years, and 921 control participants (482 men [52.3%]), with a mean (SD) age of 76.6 (11.7) years. The other group included 793 nirmatrelvir-ritonavir users (401 men [50.6%]), with a mean (SD) age of 71.7 (11.5) years, and 793 control participants (395 men [49.8%]), with a mean (SD) age of 71.9 (11.6) years. At a median follow-up of 102 days (IQR, 56-225 days), molnupiravir use was associated with a lower risk of all-cause mortality and/or hospitalization (HR, 0.71 [95% CI, 0.64-0.79]; P < .001) and in-hospital disease progression (HR, 0.49 [95% CI, 0.35-0.69]; P < .001) compared with nonuse. At a median follow-up of 85 days (IQR, 56-216 days), nirmatrelvir-ritonavir use was associated with a lower risk of all-cause mortality and/or hospitalization (HR, 0.71 [95% CI, 0.63-0.80]; P < .001) and a nonsignificantly lower risk of in-hospital disease progression (HR, 0.92 [95% CI, 0.59-1.44]; P = .73) compared with nonuse. Conclusions and Relevance: These findings suggest that both molnupiravir and nirmatrelvir-ritonavir oral antiviral medications were associated with a lower risk of all-cause mortality and hospitalization among patients with COVID-19 and type 2 diabetes. Further studies in specific populations, such as individuals in residential care homes and individuals with chronic kidney disease, are suggested.

Clinical effectiveness of nirmatrelvir plus ritonavir in patients with COVID-19 and substance use disorders based on real-world data.

This study assessed the clinical efficacy of nirmatrelvir plus ritonavir (NMV-r) in treating patients with coronavirus disease-2019 (COVID-19) and substance use disorders (SUDs). This study included two cohorts: the first examined patients with SUDs, with and without a prescription for NMV-r, while the second compared patients prescribed with NMV-r, with and without a diagnosis of SUDs. SUDs were defined using ICD-10 codes, related to SUDs, including alcohol, cannabis, cocaine, opioid, and tobacco use disorders (TUD). Patients with underlying SUDs and COVID-19 were identified using the TriNetX network. We used 1:1 propensity score matching to create balanced groups. The primary outcome of interest was the composite outcome of all-cause hospitalization or death within 30 days. Propensity score matching yielded two matched groups of 10 601 patients each. The results showed that the use of NMV-r was associated with a lower risk of hospitalization or death, 30 days after COVID-19 diagnosis (hazard ratio (HR), 0.640; 95% confidence interval (CI): 0.543-0.754), as well as a lower risk of all-cause hospitalization (HR, 0.699; 95% CI: 0.592-0.826) and all-cause death (HR, 0.084; 95% CI: 0.026-0.273). However, patients with SUDs had a higher risk of hospitalized or death within 30 days of COVID-19 diagnosis than those without SUDs, even with the use of NMV-r (HR, 1.783; 95% CI: 1.399-2.271). The study also found that patients with SUDs had a higher prevalence of comorbidities and adverse socioeconomic determinants of health than those without SUDs. Subgroup analysis showed that the benefits of NMV-r were consistent across most subgroups with different characteristics, including age (patients aged ≥60 years [HR, 0.507; 95% CI: 0.402-0.640]), sex (women [HR, 0.636; 95% CI: 0.517-0.783] and men [HR, 0.480; 95% CI: 0.373-0.618]), vaccine status (vaccinated <2 doses [HR, 0.514; 95% CI: 0.435-0.608]), SUD subtypes (alcohol use disorder [HR, 0.711; 95% CI: 0.511- 0.988], TUD [HR, 0.666; 95% CI: 0.555-0.800]) and Omicron wave (HR, 0.624; 95% CI: 0.536-0.726). Our findings indicate that NMV-r could reduce all-cause hospitalization and death in the treatment of COVID-19 among patients with SUDs and support the use of NMV-r for treating patients with SUDs and COVID-19.

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

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

Association of Molnupiravir and Nirmatrelvir-Ritonavir with reduced mortality and sepsis in hospitalized omicron patients: a territory-wide study.

This study evaluates the association between antivirals (Molnupiravir and Nirmatrelvir-Ritonavir) and all-cause and respiratory mortality and organ dysfunction among high-risk COVID-19 patients during an Omicron outbreak. Two cohorts, Nirmatrelvir-Ritonavir versus control and Molnupiravir versus control, were constructed with inverse probability treatment weighting to balance baseline characteristics. Cox proportional hazards models evaluated the association of their use with all-cause mortality, respiratory mortality, and all-cause sepsis (a composite of circulatory shock, respiratory failure, acute liver injury, coagulopathy, and acute liver impairment). Patients recruited were hospitalized and diagnosed with the COVID-19 Omicron variant between February 22, 2022 and April 15, 2022, and followed up until May 15, 2022. The study included 17,704 patients. There were 4.67 and 22.7 total mortalities per 1000 person-days in the Nirmatrelvir-Ritonavir and control groups respectively before adjustment (weighted incidence rate ratio, - 18.1 [95% CI - 23.0 to - 13.2]; hazard ratio, 0.18 [95% CI, 0.11-0.29]). There were 6.64 and 25.9 total mortalities per 1000 person-days in the Molnupiravir and control groups respectively before adjustment (weighted incidence rate ratio per 1000 person-days, - 19.3 [95% CI - 22.6 to - 15.9]; hazard ratio, 0.23 [95% CI 0.18-0.30]). In all-cause sepsis, there were 13.7 and 35.4 organ dysfunction events per 1000 person-days in the Nirmatrelvir-Ritonavir and control groups respectively before adjustment (weighted incidence rate ratio per 1000 person-days, - 21.7 [95% CI - 26.3 to - 17.1]; hazard ratio, 0.44 [95% CI 0.38-0.52]). There were 23.7 and 40.8 organ dysfunction events in the Molnupiravir and control groups respectively before adjustment (weighted incidence ratio per 1000 person-days, - 17.1 [95% CI, - 20.6 to - 13.6]; hazard ratio, 0.63 [95% CI 0.58-0.69]). Among COVID-19 hospitalized patients, use of either Nirmatrelvir-Ritonavir or Molnupiravir compared with no antiviral use was associated with a significantly lower incidence of 28-days all-cause and respiratory mortality and sepsis.

Therapeutics for COVID-19.

Vaccines and monoclonal antibody treatments to prevent severe coronavirus disease 2019 (COVID-19) illness were available within a year of the pandemic being declared but there remained an urgent need for therapeutics to treat patients who were not vaccinated, were immunocompromised or whose vaccine immunity had waned. Initial results for investigational therapies were mixed. AT-527, a repurposed nucleoside inhibitor for hepatitis C virus, enabled viral load reduction in a hospitalized cohort but did not reduce viral load in outpatients. The nucleoside inhibitor molnupiravir prevented death but failed to prevent hospitalization. Nirmatrelvir, an inhibitor of the main protease (Mpro), co-dosed with the pharmacokinetic booster ritonavir, reduced hospitalization and death. Nirmatrelvir-ritonavir and molnupiravir received an Emergency Use Authorization in the United States at the end of 2021. Immunomodulatory drugs such as baricitinib, tocilizumab and corticosteroid, which target host-driven COVID-19 symptoms, are also in use. We highlight the development of COVID-19 therapies and the challenges that remain for anticoronavirals.

Combination regimen of nirmatrelvir/ritonavir and molnupiravir for the treatment of persistent SARS-CoV-2 infection: A case report and a scoping review of the literature.

Immunocompromised patients still experience unpredictable courses of COVID-19, despite that effective vaccines and drugs against SARS-CoV-2 are now available. Antiviral combination regimens may have a role in SARS-CoV-2 infection in immunocompromised hosts, but current knowledge is still limited. We describe the case of a 73-year-old Italian man affected by follicular lymphoma with persistent SARS-CoV-2 infection who was successfully treated with co-administration of oral antivirals (10-day molnupiravir and nirmatrelvir/ritonavir). The therapy was well tolerated both from a clinical and biochemical standpoint, with no signs of toxicity. We also performed a scoping review, to sum up available knowledge on combined antiviral regimens including remdesivir, molnupiravir, or nirmatrelvir/ritonavir. Pending further studies on larger cohorts of patients, our report is consistent with available pre-clinical and clinical data, supporting the possible use of combination therapy in selected difficult-to-treat COVID-19 cases.

Safely Prescribing Nirmatrelvir and Ritonavir-Avoiding Drug-Drug Interactions.

This Teachable Moment discusses drug-drug interactions with nirmatrelvir and ritonavir (Paxlovid) treatment for COVID-19 and considerations when prescribing.

Efficacy of nirmatrelvir and ritonavir for post-acute COVID-19 sequelae beyond 3 months of SARS-CoV-2 infection.

The effect of nirmatrelvir plus ritonavir (NMV-r) on post-acute COVID-19 sequelae beyond 3 months of SARS-CoV-2 infection remains unknown. This retrospective cohort study utilized data from the TriNetX Research Network. We identified nonhospitalized adult patients with COVID-19 receiving a diagnosis between January 1 and July 31, 2022. Propensity score matching (PSM) was used to create two matched cohorts: NMV-r and non-NMV-r groups, respectively. We measured the primary outcomes using a composite of all-cause emergency room (ER) visits or hospitalization and a composite of post-COVID-19 symptoms according to the WHO Delphi consensus, which also stated that post COVID-19 condition occurs usually 3 months from the onset of COVID-19, during the follow-up period between 90 days after the index diagnosis of COVID-19 and the end of follow-up (180 days). Initially, we identified 12 247 patients that received NMV-r within 5 days of diagnosis and 465 135 that did not. After PSM, 12 245 patients remained in each group. During the follow-up period, patients treated with NMV-r had a lower risk of all-cause hospitalization and ER visits compared with untreated patients (659 vs. 955; odds ratio [OR], 0.672; 95% confidence interval [CI], 0.607-0.745; p < 0.0001). However, the overall risk of post-acute COVID-19 symptoms did not significantly differ between the two groups (2265 vs. 2187; OR, 1.043; 95% CI, 0.978-1.114; p = 0.2021). The reduced risk of all-cause ER visits or hospitalization in the NMV-r group and the similarities in the risk of post-acute COVID-19 symptoms between the two groups were consistent in the subgroups stratified by sex, age, and vaccination status. Early NMV-r treatment of nonhospitalized patients with COVID-19 was associated with reduced risk of hospitalization and ER visits during the period of 90-180 days after diagnosis compared with no NMV-r treatment; however, post-acute COVID-19 symptoms and mortality risk did not differ significantly between the groups.

Clinical Outcomes Following Treatment for COVID-19 With Nirmatrelvir/Ritonavir and Molnupiravir Among Patients Living in Nursing Homes.

Importance: Older patients living in nursing homes are at very high risk of mortality after getting COVID-19. Objective: To evaluate outcomes following oral antiviral treatment for COVID-19 among nonhospitalized older patients living in nursing homes. Design, Setting, and Participants: This is a territory-wide, retrospective cohort study conducted between February 16 and March 31, 2022, with the last follow-up date on April 25, 2022. Participants were patients with COVID-19 living in nursing homes in Hong Kong. Data analysis was performed from May to June 2022. Exposures: Molnupiravir, nirmatrelvir/ritonavir, or no oral antiviral treatment. Main Outcomes and Measures: The primary outcome was hospitalization for COVID-19, and the secondary outcome was risk of inpatient disease progression (ie, admission to intensive care unit, use of invasive mechanical ventilation, and/or death). Results: Of 14 617 patients (mean [SD] age, 84.8 [10.2] years; 8222 women [56.2%]), 8939 (61.2%) did not use oral antivirals, 5195 (35.5%) used molnupiravir, and 483 (3.3%) used nirmatrelvir/ritonavir. Compared with patients who did not use oral antivirals, those who used molnupiravir and nirmatrelvir/ritonavir were more likely to be female and less likely to have comorbid illnesses and hospitalization in the past year. At a median (IQR) follow-up of 30 (30-30) days, 6223 patients (42.6%) were hospitalized and 2307 patients (15.8%) experienced inpatient disease progression. After propensity score weighting, both molnupiravir and nirmatrelvir/ritonavir were associated with a reduced risk of hospitalization (molnupiravir, weighted hazard ratio [wHR], 0.46; 95% CI, 0.37-0.57; P < .001; nirmatrelvir/ritonavir, wHR, 0.46; 95% CI, 0.32-0.65; P < .001) and inpatient disease progression (molnupiravir, wHR, 0.35; 95% CI, 0.23-0.51; P < .001; nirmatrelvir/ritonavir, wHR, 0.17; 95% CI, 0.06-0.44; P < .001). Nirmatrelvir/ritonavir was comparable to molnupiravir in achieving better clinical outcomes (hospitalization, wHR, 1.00; 95% CI, 0.75-1.33; P = .99; inpatient disease progression, wHR, 0.49; 95% CI, 0.20-1.20; P = .12). Conclusions and Relevance: In this retrospective cohort study, the use of oral antivirals to treat COVID-19 was associated with a reduced risk of hospitalization and inpatient disease progression among patients living in nursing homes. The findings of this study of nursing home residents could be reasonably extrapolated to other frail older patients living in the community.

Nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients: A systematic review and meta-analysis.

At present, there are some differences in the research results of nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients. We aimed to evaluate the efficacy and safety of nirmatrelvir-ritonavir compared with other antiviral drugs and the impact of different antiviral drugs on the short- and long-term effects of COVID-19. PubMed, Embase, CENTRAL (Cochrane Central Register of Controlled Trials), Web of Science, Google Scholar, and MedRxiv were searched to identify relevant studies from inception to March 30, 2023. We conducted a meta-analysis to estimate the effects of nirmatrelvir-ritonavir compared with other antiviral drugs for the treatment of COVID-19 patients and safety outcomes. The RoB1 and ROBINS-I were used to assess the bias risk of the included studies. Revman 5.4 software was used for meta-analysis (PROSPERO Code No: CRD42023397816). Twelve studies were included, including 30 588 COVID-19 patients, of whom 13 402 received nirmatrelvir-ritonavir. The meta-analysis results showed that the nirmatrelvir-ritonavir group had a lower proportion of patients than the control group in terms of long-term mortality (odds ratio [OR] = 0.29, 95% confidence interval [CI]: 0.13-0.66), hospitalization (OR = 0.44, 95% CI: 0.37-0.53, short term; OR = 0.52, 95% CI: 0.36-0.77, long term), and disease progression (OR = 0.56, 95% CI: 0.38-0.83, short term; OR = 0.60, 95% CI: 0.48-0.74, long term), and nirmatrelvir ritonavir showed little difference in safety compared to the control group. Nirmatrelvir-ritonavir can reduce the mortality and hospitalization of COVID-19 patients compared with other antiviral drugs. Further large-scale studies remain to validate these findings.

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

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

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.