[Stimulation of the renal excretion of p-aminohippuric acid by probenecid homologues (author's transl)].

: Probenecid and five of its homologues showed increased lipophilicity with increasing chain length of the substituents. Parallel to this, the toxicity increased about 30 times. All the probenecide homologues under study stimulated the excretion of p-aminohippuric acid (PAH) when applied repeatedly. If a threshold dose is exceeded, an increase of the pretreatment dose will not result in a further increase in PAH excretion. As compared to non-pretreated control animals, the highest possible increase in PAH excretion lies between 40 and 80% independently of the structure of the respective probenecide homologue. Due to their more favourable therapeutic range (LD50 divided by D40-50), the probenecide homologues with shorter chains are better suited to stimulate the excretion of PAH, though the extent of stimulation is the same with all the probenicide homologues under study.