Tacrolimus is an essential immunosuppressive drug in lung transplantation. It is metabolized by cytochrome P450, which can cause interactions with many drugs. We present a case of acute tacrolimus poisoning in a lung transplant patient following administration of nirmaltrevir/ritonavir, as well as treatment with rifampicin, acytochrome inducer, which allowed blood levels of tacrolimus to be reduced to appropriate values.
