Prevention of the Precipitation of Urinary Salts with p-Aminosalicylic Acid and Closely Related Substances: In Vivo Experiments

Abstract

p-Aminosalicylic acid (PAS) and its sodium salt given orally will prevent the precipitation of most urinary salts without formation of the salt sediments normally formed after storing urines at +4°C for 12–24 hours. The duration of the effect—when collecting urine every second hour…is approximately 8 hours for a 2 g load, 10 hours for a 4 g load and 16 hours for a 8 g load. The effect is not due to acidifaction of the urine as there is no changes in pH as compared with urine collected in the same way without any PAS load. This suggests the possible use of PAS or its sodium salt for the prevention of urinary calculi since PAS has been found to have little toxicity in long-term use against tuberculosis. The treatment will be described in a forthcoming paper. The mechanism of the effect of PAS is so far unknown, but a chelating effect seems likely. p-Aminobenzoic acid and benzoic acid given in equimolar loads have an effect similar to PAS.