Antibacterial Chemotherapy

Binding to Plasma Protein The experiments of Davis307 308 309 310 and subsequent reports by the same author and others311 , 312 established that sulfonamide action depends upon the level of unbound drug in the plasma water. At therapeutic concentrations sulfanilamide is protein bound to an extent of 20 per cent, sulfapyridine 40 per cent, sulfathiazole 75 per cent, sulfadiazine 56 per cent, sulfamerazine 84 per cent, and sulfamethazine 84 per cent.289, 308 , 313 , 314 It should be noted, however, that the usual technics for determining plasma levels do not distinguish between bound and unbound drug. The accepted bacteriostatic thresholds for various organisms also refer to total (bound . . .