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Chiral Pharmacology
Definition: Chiral pharmacology is the branch of pharmacology that studies how molecular chirality influences the pharmacological behavior of drugs. It examines the stereoselective differences between enantiomers in terms of pharmacodynamics, pharmacokinetics, metabolism, therapeutic efficacy, toxicity, and clinical outcomes.
Context: Most biological macromolecules-including receptors, enzymes, ion channels, transport proteins, and nucleic acids-are inherently chiral. Consequently, individual enantiomers of a chiral drug often interact differently with these biological targets, leading to distinct pharmacological and toxicological profiles. Chiral pharmacology provides the scientific basis for understanding these stereoselective interactions and supports the rational design, development, regulatory evaluation, and clinical use of single-enantiomer drugs.
Example: Esomeprazole, the (S)-enantiomer of omeprazole, exhibits improved pharmacokinetic properties and more consistent acid suppression than the racemic formulation. Likewise, levobupivacaine demonstrates reduced cardiotoxicity compared with racemic bupivacaine, illustrating the clinical significance of chiral pharmacology.
Broader Concept: Stereopharmacology
Associated Concept: Chiral Drug
Narrower Concept: Chiral Pharmacodynamics; Chiral Pharmacokinetics
Related Terms: Chirality, Stereochemistry, Enantiomer, Chiral Drug, Stereoselectivity, Chiral Pharmacodynamics, Chiral Pharmacokinetics, Eutomer, Distomer, Chiral Switch.
Reference: Hutt, A. J., & Caldwell, J. (1985). The importance of stereochemistry in drug action and disposition. Pharmacology & Therapeutics, 29(2), 245-263.
Caldwell, J. (1995). Chiral pharmacology and the regulation of new drugs. Chemistry and Industry, 6, 176-179.
Ariens, E. J. (1984). Stereochemistry, a basis for sophisticated nonsense in pharmacokinetics and clinical pharmacology. European Journal of Clinical Pharmacology, 26, 663-668.
Agranat, I., Caner, H., & Caldwell, J. (2002). Putting chirality to work: The strategy of chiral switches. Nature Reviews Drug Discovery, 1(10), 753-768.
Nguyen, L. A., He, H., & Pham-Huy, C. (2006). Chiral Drugs: An Overview. International Journal of Biomedical Science, 2(2), 85-100.
Smith, S. W. (2009). Chiral Toxicology: It's the Same Thing... Only Different. Toxicological Sciences, 110(1), 4-30.
