A rare drug fever due to everolimus use in a patient with liver transplantation: a case report during the Covid-19 pandemic

Drug-induced fever (DIF) is an uncommon, difficult-to-diagnose complication which is one of the possible causes of fever of unknown origin (FUO). In addition, Covid-19 infection is also a cause of fever in these pandemic days we live. Everolimus (EVR), an inhibitor of the mammalian target of rapamycin (mTOR), is employed as an immunosuppressant in combination with calcineurin inhibitors, following a procedure of organ transplantation, and as a proliferation signal inhibitor coated on a drug-eluting stent and in cancer therapy. EVR has many adverse effects that require follow-up, but fever is not one of the well-known adverse effects thereof. In our literature search, we have found only a single case of fever due to EVR use which had been reported in a patient following a cardiac transplantation in 2004. On the other hand, our case is a patient with a diagnosis of alcohol-induced liver cirrhosis and hepatocellular carcinoma (HCC) who has been subjected to a liver transplantation (LT) has developed fever in the course of our follow-up just after the initiation of EVR treatment at the third month post-transplantation and during the covid-19 pandemic.