tacrolimus and nirmatrelvir

Solid organ transplant (SOT) recipients are at risk of complications from COVID-19. Nirmatrelvir/ritonavir (Paxlovid) can reduce mortality from COVID-19 but is contraindicated in patients receiving calcineurin inhibitors (CI), which depend on cytochrome p4503A (CY3PA). In this study, we aim to show the feasibility of nirmatrelvir/ritonavir administration to SOT recipients receiving CI with coordination of medication management and limited tacrolimus trough monitoring.. We reviewed adult SOT recipients treated with nirmatrelvir/ritonavir from 4/14 to 11/1/2022 and assessed for changes in tacrolimus trough and serum creatinine after therapy.. Of 47 patients identified, 28 were receiving tacrolimus and had follow-up laboratory testing. Patients had a mean age of 55 years, 17 (61%) received a kidney transplant and 23 (82%) received three or more doses of SARS-CoV-2 mRNA vaccine. Patients had mild-moderate COVID-19 and started nirmatrelvir/ritonavir within 5 days of symptom onset. Median baseline tacrolimus trough concentration was 5.6 ng/mL (Interquartile range 5.1-6.7), while median follow-up tacrolimus trough concentration was 7.8 ng/mL (Interquartile range 5.7-11.5, p = 0.0017). Median baseline and follow-up serum creatinine levels were 1.21 mg/dL (Interquartile range 1.02-1.39) and 1.21 mg/dL (interquartile range 1.02-1.44, p = 0.3162), respectively. One kidney recipient had a follow up creatinine level >1.5 times baseline. No patients were hospitalized or died from COVID-19 in the follow up period.. While administration of nirmatrelvir/ritonavir resulted in a significant increase in tacrolimus concentration, this did not result in significant nephrotoxicity. Early oral antiviral treatment in SOT recipients is feasible with medication management, even with limited tacrolimus trough monitoring.

Topics: Adult; Antiviral Agents; COVID-19; COVID-19 Drug Treatment; COVID-19 Vaccines; Creatinine; Humans; Immunosuppressive Agents; Middle Aged; Ritonavir; SARS-CoV-2; Tacrolimus

Paxlovid (nirmatrelvir/ritonavir) is a novel drug available under emergency use authorization by the Food and Drug Administration for the treatment of COVID-19 infection. Tacrolimus, a calcineurin inhibitor, is commonly used as an immunosuppressant medication in children with kidney transplants. While tacrolimus is metabolized by the cytochrome P450 system (CYP3A4), ritonavir is a potent CYP3A4 inhibitor. There is a paucity of data regarding the drug-drug interaction between nirmatrelvir/ritonavir and tacrolimus in children with kidney transplants.. This is a case report of a 14-year-old female with a history of a kidney transplant, maintained on tacrolimus and prednisone, who starts nirmatrelvir/ritonavir for a COVID-19 infection. She subsequently develops supratherapeutic tacrolimus levels and an increase in serum creatinine. Her tacrolimus was held, and the nirmatrelvir/ritonavir was stopped. Over time, her kidney function returned to baseline, her tacrolimus levels returned to the therapeutic goal, and her tacrolimus was resumed.. Our case report highlights the strong interaction with concomitant use of tacrolimus and nirmatrelvir/ritonavir in a pediatric kidney transplant recipient and the development of supratherapeutic tacrolimus levels. Providers should therefore be cautious when prescribing nirmatrelvir/ritonavir to a pediatric patient currently on tacrolimus.

Topics: Adolescent; Child; COVID-19; COVID-19 Drug Treatment; Female; Humans; Kidney Transplantation; Ritonavir; Tacrolimus; United States

Limited data and guidelines exist for using nirmatrelvir/ritonavir in solid organ transplant recipients stabilized on tacrolimus for the treatment of mild-to-moderate coronavirus disease. Concern exists regarding the impact of utilizing a 5-d course of nirmatrelvir/ritonavir with calcineurin inhibitors because of significant drug-drug interactions between ritonavir, a potent cytochrome P450 3A inhibitor, and other cytochrome P450 3A substrates, such as tacrolimus.. We report the successful use of nirmatrelvir/ritonavir in 12 outpatient lung transplant recipients with confirmed severe acute respiratory syndrome coronavirus 2 infection stabilized on tacrolimus immunosuppression. All patients stopped tacrolimus and started nirmatrelvir/ritonavir 10 to 14 h after the last dose of tacrolimus. Tacrolimus was withheld and then reinitiated at a modified dose 48 h following the completion of nirmatrelvir/ritonavir therapy. Tacrolimus trough levels were checked during nirmatrelvir/ritonavir therapy and tacrolimus reinitiation.. Ten (10/12) patients were able to resume their original tacrolimus dose within 4 d of completing nirmatrelvir/ritonavir therapy and maintain therapeutic levels of tacrolimus. No patients experienced tacrolimus toxicity or acute rejection during the 30-d postcompletion of nirmatrelvir/ritonavir therapy.. In this cohort of lung transplant recipients on tacrolimus, we demonstrated that nirmatrelvir/ritonavir can be safely used with close monitoring of tacrolimus levels and appropriate dose adjustments of tacrolimus. Further confirmatory studies are needed to determine the appropriate use of therapeutic drug monitoring and tacrolimus dose following completion of nirmatrelvir/ritonavir in the solid organ transplant population.

Topics: COVID-19; COVID-19 Drug Treatment; Cytochrome P-450 CYP3A; Humans; Immunosuppressive Agents; Lung; Ritonavir; Tacrolimus; Transplant Recipients

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or COVID-19) pandemic has had a significant impact on communities and health systems. The Federal Drug Administration (FDA) authorized Pfizer's nirmatrelvir/ritonavir (Paxlovid™) through an EUA for the treatment of mild to moderate cases of COVID-19 at high risk for progression to severe disease. Patients with a history of transplant who test positive for COVID-19 are considered high risk because of their immunosuppression and are therefore candidates for nirmatrelvir/ritonavir.. This is a case of a 67-year-old female with a past medical history of orthotopic heart transplant who received tacrolimus as part of her immunosuppressive regimen. She originally presented with complaints of dyspnea and cough for several days in the setting of COVID-19. The patient was started on nirmatrelvir/ritonavir due to her high risk for progression to severe disease. Four days after starting nirmatrelvir/ritonavir, she presented to the ED for slowed speech, fatigue, weakness, and loss of appetite. Upon admission she was found to have a supratherapeutic tacrolimus level of 176.4 ng/mL and an acute kidney injury. In this case, phenytoin was used as a CYP3A4 inducer to quickly decrease the tacrolimus level to within therapeutic range.. This case highlights the strong and important drug-drug interaction between tacrolimus and nirmatrelvir/ritonavir leading to toxic levels of tacrolimus. It also demonstrates the utility and effectiveness of phenytoin as a "rescue" medication for tacrolimus toxicity.

Topics: Aged; COVID-19; COVID-19 Drug Treatment; Drug Interactions; Female; Humans; Phenytoin; Ritonavir; SARS-CoV-2; Tacrolimus

Topics: Drug Monitoring; Humans; Ritonavir; Tacrolimus

Topics: Humans; Phenytoin; Ritonavir; Tacrolimus

Topics: Humans; Phenytoin; Ritonavir; Tacrolimus

Nirmatrelvir/ritonavir, a newly authorized drug for the treatment of COVID-19, is a strong CYP3A4 inhibitor that can interact with many drugs, such as tacrolimus, reducing its metabolism. The reported case is a renal transplant patient who experienced a strong increase in tacrolimus blood concentration (up to 112ng/mL, more than ten times above the target range) when treated with both drugs at the same time, which caused a neurologic condition that required hospital admission for its control and treatment. The resolution of the symptoms was rapid, but the elevation of tacrolimus concentration remained for several days, even after discontinuing both drugs. This case shows the importance of developing a protocol for managing this interaction to guarantee the efficacy and safety of treatment with nirmatrelvir/ritonavir in transplant patients.

Topics: Antiviral Agents; COVID-19; COVID-19 Drug Treatment; Humans; Ritonavir; Tacrolimus

Tacrolimus is commonly used for immunosuppression in patients following solid organ transplantation. For transplant patients with COVID-19 infection, early treatment is indicated due to the risk of progression to severe disease. However, the first line agent, nirmatrelvir/ritonavir, has multiple drug-drug interactions. We report a case of tacrolimus toxicity in a patient with a history of renal transplant due to enzyme inhibition related to nirmatrelvir/ritonavir. An 85-year-old woman with a history of multiple comorbidities presented to the emergency department (ED) with weakness, increasing confusion, poor oral intake, and inability to walk. She had been recently diagnosed with COVID-19 infection and was prescribed nirmatrelvir/ritonavir due to her underlying comorbidities and immune suppression. In the ED, she was dehydrated and had an acute kidney injury (creatinine 2.1 mg/dL, up from a baseline of 0.8 mg/dL). The tacrolimus concentration on initial labs was 143 ng/mL (5-20 ng/mL) and it continued to rise despite being held, to a peak of 189 ng/mL on hospital day 3. The patient was treated with phenytoin for enzyme induction and the tacrolimus concentration began to fall. She was discharged to a rehabilitation facility after a 17 day hospitalization. ED physicians must be cognizant of drug-drug interactions when prescribing nirmatrelvir/ritonavir and evaluating patients recently treated with the drug to identify toxicity due to these interactions.

Topics: Aged, 80 and over; Antiviral Agents; COVID-19; COVID-19 Drug Treatment; Female; Humans; Ritonavir; Tacrolimus

Nirmatrelvir/ritonavir (NR) use has not yet been described in solid organ transplant recipients (SOTRs) with mild COVID-19. The objective was to evaluate outcomes among SOTR and describe the drug-drug interaction of NR. This is an IRB-approved, retrospective study of all adult SOTR on a calcineurin inhibitor (CNI) or mammalian target of rapamycin inhibitor who were prescribed NR between December 28, 2021 and January 6, 2022. A total of 25 adult SOTR were included (n = 21 tacrolimus, n = 4 cyclosporine, n = 3 everolimus, n = 1 sirolimus). All patients were instructed to follow the following standardized protocol during treatment with 5 days of NR: hold tacrolimus or mTOR inhibitor or reduce cyclosporine dose to 20% of baseline daily dose. Four patients (16%) were hospitalized by day 30; one for infectious diarrhea and three for symptoms related to COVID-19. No patients died within 30 days of receipt of NR. Median tacrolimus level pre- and post-NR were 7.4 ng/ml (IQR, 6.6-8.6) and 5.2 (IQR, 3.6-8.7), respectively. Four patients experienced a supratherapeutic tacrolimus concentration after restarting tacrolimus post-NR. Our results show the clinically significant interaction between NR and immunosuppressive agents can be reasonably managed with a standardized dosing protocol. Prescribers should carefully re-introduce CNI after the NR course is complete.

Topics: Adult; Calcineurin Inhibitors; COVID-19 Drug Treatment; Cyclosporine; Graft Rejection; Humans; Immunosuppressive Agents; Lactams; Leucine; Nitriles; Organ Transplantation; Proline; Retrospective Studies; Ritonavir; Sirolimus; Tacrolimus; Transplant Recipients