Prolongation of Penicillin Activity with Penicillinase-Inhibiting Compounds

Penicillin blood serum levels can be prolonged by the administration of penicillin with sodium sulfanilate, sodium benzoate, bromsaligenin or certain other compounds. 2. Effect of bromsaligenin on penicillin has been demonstrated in vitro to be due to inhibition of growth of Esch. coli and other Gram-negative intestinal bacteria. 3. The effect of sodium benzoate or sodium sulianilate on penicillin has been shown in vitro to be due to inhibition, at least temporarily, of the enzyme penicillinase. 4. That such drugs are useful and effective in prolonging penicillin levels in the blood and so increasing the efficiency of penicillin has been shown by in vivo tests in mice and rabbits. 5. A list of compounds that do not possess this quality has been given, as well as some chemicals that give questionable results.