Non-specific plasma proteins and extracellular fluid

Non-specific plasma proteins and extracellular fluid represent the physiological compartments and circulating proteins that interact with drugs but do not typically serve as the primary site of therapeutic action (StatPearls, 2023). Plasma proteins, most notably human serum albumin and alpha-1-acid glycoprotein, play a critical role in drug pharmacokinetics by binding to various ligands, thereby limiting the concentration of free, active drug in the systemic circulation (PubMed, 2021). The extracellular fluid, comprising interstitial fluid and plasma, serves as the medium through which drugs distribute to reach their specific cellular targets (NIH, 2022). While not therapeutic targets themselves, these components are vital for determining a drug's volume of distribution, half-life, and potential for drug-drug interactions (Wikipedia, 2024). Alterations in the composition of these fluids or protein concentrations, such as in liver disease or malnutrition, can significantly impact drug efficacy and safety profiles (NCBI, 2023).

Other names

Plasma proteinsSerum proteinsExtracellular fluidECFInterstitial fluid

Non-specific binding to plasma proteins (primarily albumin and alpha-1-acid glycoprotein) and distribution within the extracellular fluid volume, which influences the free fraction of drug available for therapeutic action and elimination (StatPearls, 2023).