Changes in Expression and Function of Placental and Intestinal P-gp and BCRP Transporters during Pregnancy.

ABC transporters are ubiquitous in the human body and are responsible for the efflux of drugs. They are present in the placenta, intestine, liver and kidney, which are the major organs that can affect the pharmacokinetic and pharmacologic properties of drugs. P-gp and BCRP transporters are the best-characterized transporters in the ABC superfamily, and they have a pivotal role in the barrier tissues due to their efflux mechanism. Moreover, during pregnancy, drug efflux is even more important because of the developing fetus. Recent studies have shown that placental and intestinal ABC transporters have great importance in drug absorption and distribution. Placental and intestinal P-gp and BCRP show gestational-age-dependent expression changes, which determine the drug concentration both in the mother and the fetus during pregnancy. They may have an impact on the efficacy of antibiotic, antiviral, antihistamine, antiemetic and oral antidiabetic therapies. In this review, we would like to provide an overview of the pharmacokinetically relevant expression alterations of placental and intestinal ABC transporters during pregnancy.