Drug-herbal interaction between tacrolimus and rooibos tea in a recipient of allogeneic hematopoietic stem cell transplantation

Abstract

Tacrolimus has been widely used for the prophylaxis and treatment of graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation. Since tacrolimus is mainly metabolized by cytochrome P450 (CYP) enzymes, its drug interaction with a variety of agents has been clinically recognized. In addition, natural products such as food components and herbal products have also been reported to interact with tacrolimus. We here report the first case of a drug interaction between tacrolimus and rooibos tea documented after allogeneic hematopoietic stem cell transplantation, in which the interaction reduced the concentration of tacrolimus and resulted in the development of GVHD. Transplant physicians and pharmacists should be made aware of the drug-herbal interaction between rooibos tea and tacrolimus, which is probably applicable to other drugs metabolized by CYP enzymes, such as cyclosporine A.