PROTON PUMP INHIBITORS AND TACROLIMUS

Lansoprazole may increase tacrolimus levels in patients with low CYP2C19 levels. Omeprazole (and therefore probably esomeprazole) and pantoprazole are predicted to interact similarly.
It would seem prudent to consider monitoring tacrolimus levels as it is unlikely that CYP2C19 metaboliser status is known. Rabeprazole may be a suitable alternative proton pump inhibitor, as limited evidence suggests that it does not interact, and nor would it be expected to do so.