The intent is to provide a list of sources and a summary of the best evidence on the topic that CADTH could identify using all reasonable efforts within the time allowed. [...] The authors concluded that for renal transplant recipients with certain genetic variations, rabeprazole and lansoprazole may inhibit the metabolism of tacrolimus and lower dosages should be given. [...] These findings indicate that the administration of lansoprazole in patients with certain genetic variations may potentially diminish the absorption of MPA and increase the risk for acute rejection. [...] The authors concluded that the case indicates that rabeprazole can safely be used in place of omeprazole in renal transplant patients receiving tacrolimus. [...] PPIs in Renal Transplant Patients 5 Limitations Evidence for the use of PPIs in renal transplant recipients is limited to two small RCTs of short duration and various observational studies and case reports.