Biomaterial Database

Displacement of albumin-bound antimicrobial agents by bilirubin. 1976

D Bratlid, and T Bergan

The ability of bilirubin to displace antimicrobial agents from their binding sites on albumin was studied in vitro by equilibrium dialysis. Sulfonamides, tetracyclines, penicillins and cephalosporins of different degrees of protein binding were tested. It was found that bilirubin reduced the protein binding of all four classes of antimicrobial agents, although by varying degrees. This effect was most pronounced with the compounds which had the highest degree of protein binding, such as cloxacillin, cephazolin, methacycline and sulfisoxazole, all of which are bound greater than 80% by albumin. On the other hand, the drugs with less than 25% binding, such as ampicillin, cephalexine and tetracycline were not ostensibly displaced by bilirubin. Scatchard plots of the binding of sulfamethoxazole to albumin in the presence of 400 mumol/1 of bilirubin, showed that bilirubin almost completely displaced the sulfonamide molecule from the high affinity site on the albumin molecule. Reduced protein binding of drugs in hyperbilirubinemic infants may have pharmacokinetic significance.

UI	MeSH Term	Description	Entries
D010406	Penicillins	A group of antibiotics that contain 6-aminopenicillanic acid with a side chain attached to the 6-amino group. The penicillin nucleus is the chief structural requirement for biological activity. The side-chain structure determines many of the antibacterial and pharmacological characteristics. (Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1065)	Antibiotics, Penicillin,Penicillin,Penicillin Antibiotics
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D002511	Cephalosporins	A group of broad-spectrum antibiotics first isolated from the Mediterranean fungus ACREMONIUM. They contain the beta-lactam moiety thia-azabicyclo-octenecarboxylic acid also called 7-aminocephalosporanic acid.	Antibiotics, Cephalosporin,Cephalosporanic Acid,Cephalosporin,Cephalosporin Antibiotic,Cephalosporanic Acids,Acid, Cephalosporanic,Acids, Cephalosporanic,Antibiotic, Cephalosporin,Cephalosporin Antibiotics
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000890	Anti-Infective Agents	Substances that prevent infectious agents or organisms from spreading or kill infectious agents in order to prevent the spread of infection.	Anti-Infective Agent,Anti-Microbial Agent,Antimicrobial Agent,Microbicide,Microbicides,Anti-Microbial Agents,Antiinfective Agents,Antimicrobial Agents,Agent, Anti-Infective,Agent, Anti-Microbial,Agent, Antimicrobial,Agents, Anti-Infective,Agents, Anti-Microbial,Agents, Antiinfective,Agents, Antimicrobial,Anti Infective Agent,Anti Infective Agents,Anti Microbial Agent,Anti Microbial Agents
D001663	Bilirubin	A bile pigment that is a degradation product of HEME.	Bilirubin IX alpha,Bilirubin, (15E)-Isomer,Bilirubin, (4E)-Isomer,Bilirubin, (4E,15E)-Isomer,Bilirubin, Calcium Salt,Bilirubin, Disodium Salt,Bilirubin, Monosodium Salt,Calcium Bilirubinate,Hematoidin,delta-Bilirubin,Bilirubinate, Calcium,Calcium Salt Bilirubin,Disodium Salt Bilirubin,Monosodium Salt Bilirubin,Salt Bilirubin, Calcium,delta Bilirubin
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D012709	Serum Albumin	A major protein in the BLOOD. It is important in maintaining the colloidal osmotic pressure and transporting large organic molecules.	Plasma Albumin,Albumin, Serum
D013449	Sulfonamides	A group of compounds that contain the structure SO2NH2.	Sulfonamide,Sulfonamide Mixture,Sulfonamide Mixtures,Mixture, Sulfonamide,Mixtures, Sulfonamide
D013754	Tetracyclines	Closely congeneric derivatives of the polycyclic naphthacenecarboxamide. (Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 8th ed, p1117)