The present invention relates to a method of suppressing organ rejection in a patient receiving an organ transplant by initiating oral treatment with a once-daily extended release tacrolimus dosage form, for example, at an initial dose of from about 0.15 to about 0.20 mg/kg/day within 24 or 48 hours following transplantation. The once-daily extended release tacrolimus dosage form (i) provides low fluctuation and/or swing of tacrolimus, (ii) provides a significantly lower Cmax than an immediate release formulation of tacrolimus while providing the same or greater area under the curve (AUC), (iii) releases the tacrolimus substantially in the colon and/or the lower ileum, (iv) releases at most 63.5% of the tacrolimus in the dosage form at the 12 hour time point, or (v) any combination of any of the foregoing.
