Discussion
The commercialization of new drugs for the treatment of SARS-CoV-2 changes the conception and therapeutic management of this infection, offering alternatives with proven efficacy. The exclusion of kidney transplant patients from many of the clinical trials increases the uncertainty regarding the efficacy and safety of these drugs in patients with this condition, but this should not be a contraindication for their use, since there are studies that demonstrate benefit when used appropriately (4, 5).
Regarding the management of tacrolimus interaction with nirmatrelvir/ritonavir, there is little published evidence. Most studies (6-8) propose a similar plan of action: discontinue immunosuppressant before starting treatment with nirmatrelvir/ritonavir, and restart it at reduced doses, according to tacrolimus blood concentrations. Dose adjustment of the immunosuppressant during and after antiviral treatment should always be individualized according to the needs of each patient, and should be subjected to closer monitoring of tacrolimus blood concentrations than usual.
The reported case shows the strong elevation of tacrolimus blood concentrations caused by the interaction with nirmatrelvir/ritonavir, and its persistence over time, as well as the clinical manifestations that may develop, exposing the need to establish a standardized protocol for the management of transplanted patients prescribed these drugs.
The information flow between health care personnel and patients is also crucial in cases such as the one described in this study, and has an impact on the patient’s understanding of the modifications to his or her treatment.