Current controversies on generic substitution in the transplant community

Abstract

For drugs with a narrow therapeutic index (NTI) like tacrolimus, small changes in dosage can lead to significant changes in blood levels, which can affect both the effectiveness of the drug and the risk of adverse effects. Monitoring is crucial to ensure that the drug is maintained within the desired therapeutic range. Too low levels could lead to organ rejection, while too high levels could lead to toxicity, which can damage the kidneys, liver, and other organs. When it comes to medications with a narrow therapeutic index, like tacrolimus, the issue of generic substitution becomes more complex. Due to the narrow therapeutic index, small variations in drug concentration can lead to significant differences in clinical outcomes. Generic drugs must be proven to be bioequivalent to the brand-name drug, which means they should have similar bioavailability (rate and extent of drug absorption) when administered under the same conditions. It's important for individuals taking tacrolimus to communicate closely with their pharmacists, adhere to their prescribed dosage, attend all recommended follow-up appointments, and report any unusual symptoms or side effects promptly.