Procaine Penicillin Administered Orally: Comparison with Sodium Penicillin

Abstract

There are to our knowledge, only two reports on the oral administration of procaine penicillin (1, 2), and in both of these reports, comparisons have been made between procaine and sodium penicillin, but the conclusions drawn are strikingly dissimilar. On the one hand, when a comparison of 500,000 unit doses was made, it has been stated that “crystalline procaine penicillin G appeared in the serum in a much lower concentration and disappeared more rapidly than did crystalline sodium penicillin G” (1), and on the other, when a comparison of 200,000 unit doses was made, the averages of the plasma concentrations and the urinary recoveries that resulted from the use of buffered tablets of procaine penicillin and a buffered tablet of potassium penicillin, did not differ significantly (2). It should be stated that the conditions under which procaine and sodium penicillins were compared were not the same in the two studies. In the one case, the penicillins were administered to patients in the fasting state (1), and in the other the penicillin was administered shortly after a meal (2) ; furthermore, in one instance, different groups of patients were compared (1), whereas in the other the same group of patients was compared (2) when given the two types of penicillin. Because of the disagreement in the results reported on the comparison of orally administered procaine and sodium penicillins, the following study was conducted.