Non-specific plasma proteins

Non-specific plasma proteins refer to the heterogeneous group of proteins found in blood plasma, including albumin, globulins, and fibrinogen, which collectively maintain physiological homeostasis (StatPearls, 2023). These proteins are essential for regulating oncotic pressure and serving as carriers for hormones, lipids, and vitamins throughout the circulatory system (NCBI, 2022). In pharmacology, they are significant because many drugs bind to them—most notably to human serum albumin and alpha-1-acid glycoprotein—which dictates the drug's distribution and its free, active concentration (PubMed, 2021). While they are not therapeutic targets in the sense of being modulated to treat a specific disease, they are critical factors in pharmacokinetic modeling and drug safety (DrugBank, 2024). Variations in the concentration of these proteins, often caused by liver or kidney disease, can lead to significant changes in drug efficacy and the risk of adverse effects due to shifts in the free drug fraction (NIH, 2023).

Other names

Serum proteinsBlood proteinsPlasma protein binding sitesCirculating proteins

Non-specific reversible binding to drug molecules, primarily through hydrophobic and electrostatic interactions, which sequesters drugs in the vascular compartment and limits the free fraction available for tissue distribution and pharmacological activity.