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Influence of bupivacaine on mepivacaine protein binding
Author(s) -
Hartrick C T,
Dirkes W E,
Coyle D E,
Raj P Prithvi,
Denson D D
Publication year - 1984
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1984.217
Subject(s) - mepivacaine , bupivacaine , chemistry , displacement (psychology) , albumin , pharmacology , biochemistry , medicine , psychology , psychotherapist
To elucidate the mechanism of any drug displacement interaction, we examined the protein binding of mixtures of mepivacaine and bupivacaine in serum and solutions of albumin or α 1 ‐acid glycoprotein. Protein binding data with mepivacaine alone were best described by a model with one class of binding site and a partitioning constant in serum and by a model with one class of binding site in both isolated protein solutions. Binding affinity of mepivacaine in serum was reduced in the presence of bupivacaine. Displacement of mepivacaine by bupivacaine was observed when an α 1 ‐acid glycoprotein solution was studied. Classic competitive inhibition was demonstrated. Bupivacaine reduced mepivacaine binding to albumin, but the degree of displacement was not significant. When administered simultaneously, these two amino‐amide local anesthetics interact synergistically to produce a higher than expected free concentration of mepivacaine. This interaction increases the risk of toxicity. Clinical Pharmacology and Therapeutics (1984) 36, 546–550; doi: 10.1038/clpt.1984.217