ABSTRACT
Introduction: COVID-19 infection causes high morbidity,mortality and burden to the healthcare system.Solid organ transplant patients with COVID-19 have been reported to have between 13-30% rate of mortality.Over the past 2 years,treatment of COVID-19 has evolved with new drugs being introduce such as Molnupiravir which reported to reduce death and hospitalization up to 50%.Recently a new novel drug Paxlovid (Nirmatrelvir/Ritonavir) develop by Pfizer has shed much hope in terms of managing COVID-19 patient especially in those with solid organ transplant.However,there is not much data in using Paxlovid for kidney transplant with COVID-19.Paxlovid is known to have drug-drug interaction with medication that is highly dependent on CYP3A4 which is a member of Cytochrome P450 enzyme for clearance.It is advice to withhold certain calcineurin inhibitor drugs if on Paxlovid.However,there was no mention on withholding cyclosporin which is one of the drugs in in kidney transplant patient.We've reported the first case in literature of a kidney transplant patient on cyclosporin diagnose with COVID 19 on Paxlovid. Method(s): Our patient is a End Stage Renal Disease on regular hemodialysis for a year.He subsequently had a living related renal transplant.He was vaccinated and boosted with SARS-CoV-2 Vaccine from Pfizer BioNTech.Baseline creatinine level was 126 umol/L.Immunosuppressants are Cyclosporin 50mg BD,Prednisolone 7.5mg OD and Azathioprine 50mg OD.Baseline cyclosporin trough level was 113ng/ml.He was well until SARS-CoV-2 Rapid Test Kit was positive on day four of illness.Serum Creatinine level was 137 umol/L.His estimated Glomerular Filtration Rate was 53 ml/min/1.73m2.Chest Radiograph shows ground glass opacity on both lower zone.Patient was treated for COVID-19 Pneumonia Category 3A.In view eGFR was 53 ml/min/1.73m2,Paxlovid was started at adjusted dose (Nirmatrelvir 150mg/Ritonavir 100mg BD).Patient had four doses of Paxlovid before we were able to send cyclosporin level on day three of his admission due to logistic problem.Cyclosporin trough level was 737 ng/ml and we withheld his cyclosporin.Paxlovid was continued and there was improvement in terms of his symptoms.Serial chest radiographs showed improvement as in Figure 1.We were able to monitor his cyclosporin trough level and serum creatinine on daily basis as shown in Figure 2 and Figure 3 respectively.He completed five days of Paxlovid.On day seven of admission,cyclosporin was restarted back at 25mg BD. [Formula presented] [Formula presented] [Formula presented] Results: He was discharged well with cyclosporin dose being adjusted back to his old dose.We followed him up as outpatient and monitor his cyclosporin level which was stable and continued on his old immunosuppressant regime. Conclusion(s): This case highlights the potential treatment with Paxlovid in patients with kidney transplant on cyclosporin diagnosed to have COVID-19 infection.Drug-drug interaction between cyclosporin and Paxlovid needs to be taken into account.Moving forward in the endemic era,there will be increase usage of Paxlovid that can help to reduce severity,hospital admission and mortality in solid organ transplant with COVID-19 infection.Close monitoring of cyclosporin level,proper mitigation strategy,adjustment of immunosuppressants and safe prescription of Paxlovid will be beneficial for kidney transplant patient infected with COVID-19.This can help in reducing morbidity and mortality in our kidney transplant patients. No conflict of interestCopyright © 2023