SULFONAMIDE COMPOUNDS AND PENICILLIN

Penicillin and one of the sulfonamide compounds are frequently used simultaneously in treatment of serious infections in an attempt to enhance the therapeutic effect. Ungar, 1 in 1943, reported that sulfapyridine potentiated the action of penicillin, both in vitro and in a limited number of infected mice. Soo-Hoo and Schnitzer 2 confirmed Ungar's claim that penicillin and various sulfonamide drugs were synergistic in combatting streptococcic infections in mice. They also showed that penicillin could prevent the inhibiting action of paraaminobenzoic acid on the sulfonamide drugs. This observation suggested that, although penicillin and the sulfonamide drugs are presumed to act by different mechanisms, the combined effect might be greater than a summation and might represent a potentiation due to the inhibition by penicillin of the action of paraaminobenzoic acid present in pus and exudates and even in normal tissue fluids. T'ung 3 studied the in vitro effects of sodium sulfathiazole and