Tissue binding of antimicrobials: A brief review

Abstract

The binding of antimicrobials to various constituents of tissue is reviewed. Binding to interstitial fluid proteins is of major importance only for drugs with a high binding affinity for serum albumin. The polymyxin and polyene antibiotics bind to cell membranes. Interaction of antimicrobials with the large cell membrane mass in the body can markedly affect drug distribution. Binding to cell membranes also appears to account for the toxicity of these antibiotics. Various antimicrobials, primarily organic anions, bind to soluble intracellular proteins such as ligandin, hemoglobin and carbonic anhydrase. These proteins, especially ligandin, may be important in the cellular uptake and transport of drugs by specialized tissues such as liver, kidney and small intestine. Aminoglycoside antibiotics bind to other nonsoluble intracellular substances. This interaction may be important in toxicity to these drugs, but can also result in reduced activity in pus and necrotic tissue.