The Combined Effect of Protein-Binding and Beta-Lactamases on the Activity of Penicillins and Cephalosporins

  • Sydney Selwyn
  • Charles Lam
Part of the Chemotherapy book series (CT, volume 5)


Although the practical significance of protein-binding by antibiotics remains controversial, its potential importance is underlined by the therapeutic need for maximal tissue levels, especially with bacteriocidal drugs of the penicillin and cephalosporin groups. Yet, despite startling variations in protein-binding among members of the two groups, the effects of this parameter on antibiotic action have been largely ignored by investigators. Similarly, the therapeutic implications of wide differences in resistance to beta-lactamases among these antibiotics have long awaited a fully comparative and realistic evaluation. Studies have therefore been conducted into these two potential impediments to adequate antibiotic therapy, both individually and when combined. Parallel experiments were performed on benzylpenicillin, ampicillin, amoxycillin, methicillin, cloxacillin, flucloxacillin, carbenicillin, cephaloridine, cephalothin, cephalexin, cephradine and cephazolin.


Minimum Inhibitory Concentration Proteus Mirabilis Peptone Water Doubling Dilution Klebsiella Aerogenes 


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Copyright information

© Plenum Press, New York 1976

Authors and Affiliations

  • Sydney Selwyn
    • 1
  • Charles Lam
    • 1
  1. 1.Department of BacteriologyWestminster Medical SchoolLondonUK

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