Non-specific physiological substrates

Non-specific physiological substrates is a generic descriptor rather than a specific molecular target such as a protein, enzyme, or receptor. In pharmacology, this term is frequently used to categorize drugs that do not exert their effects through specific macromolecular binding sites but instead interact with a broad range of endogenous substances or alter the physical-chemical environment of the body (Goodman & Gilman's The Pharmacological Basis of Therapeutics). Examples include osmotic laxatives, which interact with water and electrolytes in the intestinal lumen, or antacids, which neutralize gastric hydrochloric acid (StatPearls, "Antacids"). Because this term encompasses a diverse and unrelated set of molecules, it lacks the specificity required for modern drug discovery and target validation. Consequently, it is often treated as a placeholder or an "incorrect" target designation in structured biological databases when a specific molecular mechanism is absent or involves multiple, diffuse physiological components (DrugBank Online).

Other names

Endogenous substratesPhysiological substratesNon-specific targets

Drugs targeting non-specific physiological substrates typically act through physical or chemical mechanisms, such as neutralization of acidity, osmotic gradient shifts, or non-selective adsorption of toxins, rather than high-affinity binding to a specific protein.