Spice-drug interactions: a case report on the use of turmeric, curry and ginger in a renal transplant patient on tacrolimus

Tacrolimus is a widely used immunosuppressant for the prevention of rejection after transplantation. In vitro studies suggest that interactions exist between spices and tacrolimus. We present the case of a renal transplant patient aged around 70 years who was treated with prednisone, mycophenolate-mofetil and tacrolimus. The patient had a pre-transplant dietary habit of consuming foods spiced with turmeric, curry and ginger. The following protocol was implemented in parallel with close monitoring of plasma tacrolimus concentrations: administration of 10 g/day of turmeric for 4 days, then 10 g/day of curry for 4 days and then 10 g/day of ginger for 4 days. No change in tacrolimus plasma concentrations during and after the implementation of the protocol was observed. The impact of turmeric, curry and ginger on plasma tacrolimus concentrations seems negligible in vivo although further studies are needed. A shared decision to test the impact of spice consumption in a patient with dietary habits involving these spices seems reasonable.