Chapter 11. Transporter Drug–Drug Interactions: Regulatory Requirements and Drug Labelling

The requirement for data on the inhibition and involvement of transporters in the pharmacokinetics of drugs in regulatory applications has increased considerably over the last few decades as the knowledge around drug transporters has evolved and regulatory guidance documents have been regularly updated. Drug interactions guidance from the European Medicines Agency (EMA), US Food and Drug Administration (FDA) and Japanese Ministry of Health, Labour and Welfare (MHLW)/Pharmaceuticals and Medical Devices Agency (PMDA) gives detailed information on the data that are recommended in applications, including decision trees on the need to study specific transporters. This chapter will describe strategies to determine the potential for drug interactions and the exposure of the drug in all sub-populations with altered transport protein activity, and how such data should be presented in the drug labels. Alongside this, the process for submission of new drug applications to respective agencies is described, including processes for obtaining advice from the respective agencies with particular emphasis on transporter mediated interactions.