This is a great question, @rowdyramsey, and @gaylea is correct.
Tacrolimus is a generic version and cheaper. I used to be on Prograf (brand name) and was switched to the Tacrolimus when it (generic) became available. My labs and I did not experience any changes, although my costs were reduced!
I have been taking Tacrolimus for most of almost all of my 11 years with my transplant. And still do today.
I have a routine prograf lab kit that is tested at Mayo to monitor the level of prograf in my blood. It has to be within a target range that is individual for every patient and organ. On occation my dosage has been adjusted to keep me at the best level for me. Not too high, Not too low, but just right. 😊
What have your doctors said about the rash? Do they think there is a connection to the medication? Other than the rash, How are you getting along?