This was a single-center, prospective, randomized and controlled study to evaluate the influence of pharmaceutical intervention in tacrolimus intra-subject variability during the first 3 months after transplantation. The authors designed the protocol, acquired and maintained the data, and conducted the statistical analysis. The protocol was approved by an independent ethics committee. All subjects signed a written informed consent before enrollment and the study was conducted according to good clinical practices and declaration of Helsinki. This study was conducted at Hospital do Rim between February 2014 and December 2014, 128 randomized and were followed for 3 months after transplantation.