Organic anion-transporting polypeptides (OATPs) are a family of membrane transporters found in organs and tissues throughout the body that facilitate the movement of various compounds into a cell. While OATPs serve many purposes, certain OATPs play an important role in the pharmacokinetics of drugs, affecting how the drug is absorbed, distributed, metabolized, and excreted. OATPs 1A2, 1B1, 1B3, and 2B1 are the most important for the movement of drugs throughout the body.^[1]

The function of OATPs can be affected by genetics and compounds found in food, medications, and supplements. When the activity of OATPs is altered, drug levels may be higher or lower than expected, potentially impacting drug efficacy and the risk of adverse effects.^[1][2]

For example, OATPs found along the gastrointestinal tract transport some drugs (OATP substrates) into intestinal cells, facilitating their absorption into the body. When intestinal OATP activity is inhibited, the absorption of an OATP substrate can be reduced, leading to decreased drug levels.^[2][1]

Alternatively, OATPs in the liver transport drugs into liver cells where they can be metabolized. In this case, the inhibition of liver OATP activity could lead to reduced drug metabolism and increased drug levels.^[1]