The Concept of Fraction of Drug Transported (f(t)) With Special Emphasis on BBB Efflux of CNS and Antiretroviral Drugs

摘要

The fraction of drug transported (f(t)) into or out of a tissue is a concept useful to understand the impact of transporters on absorption, distribution, metabolism, and excretion (ADME) and tissue distribution of a drug. Here, f(t) is utilized to explain the impact of transporters on central nervous system (CNS) distribution of drugs, drug interactions (DDI), and to predict the unbound brain concentration (C-u,C-b) of the drug. The latter is important to ascertain if C-u,C-b is sufficient for efficacy.