**Role of OATP1B1 and OATP1B3 in Drug-Drug Interactions Mediated by Tyrosine Kinase Inhibitors**

**Dominique A. Garrison** †**, Zahra Talebi** †**, Eric D. Eisenmann, Alex Sparreboom \* and Sharyn D. Baker \***

Division of Pharmaceutics and Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA; garrison.220@osu.edu (D.A.G.); talebi.9@osu.edu (Z.T.); eisenmann.11@osu.edu (E.D.E.)

**\***Correspondence: sparreboom.1@osu.edu (A.S.); baker.2480@osu.edu (S.D.B.);

Tel.: +1-614-685-6014 (A.S.); +1-614-685-6016 (S.D.B.)

† These authors contributed equally to this work.

Received: 15 August 2020; Accepted: 2 September 2020; Published: 9 September 2020

**Abstract:** Failure to recognize important features of a drug's pharmacokinetic characteristics is a key cause of inappropriate dose and schedule selection, and can lead to reduced efficacy and increased rate of adverse drug reactions requiring medical intervention. As oral chemotherapeutic agents, tyrosine kinase inhibitors (TKIs) are particularly prone to cause drug-drug interactions as many drugs in this class are known or suspected to potently inhibit the hepatic uptake transporters OATP1B1 and OATP1B3. In this article, we provide a comprehensive overview of the published literature and publicly-available regulatory documents in this rapidly emerging field. Our findings indicate that, while many TKIs can potentially inhibit the function of OATP1B1 and/or OATP1B3 and cause clinically-relevant drug-drug interactions, there are many inconsistencies between regulatory documents and the published literature. Potential explanations for these discrepant observations are provided in order to assist prescribing clinicians in designing safe and effective polypharmacy regimens, and to provide researchers with insights into refining experimental strategies to further predict and define the translational significance of TKI-mediated drug-drug interactions.

**Keywords:** OATP1B1; OATP1B3; tyrosine kinase inhibitors; drug-drug interactions
