Probenecid Aminosalicylates

AMINOSALICYLATES ANTIGOUT DRUGS -PROBENECID Aminosalicylate levels t by probenecid Probenecid competes with aminosalicylate for active renal excretion Watch for early features of toxicity of aminosalicylate. Consider 1 dose of aminosalicylate... 

Aminosalycylic Acid Dose forms should be freshly prepared, since aqueous solutions are unstable. Aminosalicylate acid interacts with other salicylates, such as probenecid and procaine. 

Spector R, Lorenzo AV (1974) The effects of salicylate and probenecid on the cerebrospinal fluid transport of penicillin, aminosalicylic acid and iodide. J Pharmacol Exp Ther 188 55—65. 

The plasma levels of aminosalicylic acid can be raised up to fourfold by probenecid. 

In a study in 7 patients, probenecid 500 mg every 6 hours increased the plasma levels of aminosalicylic acid 4 g by as much as fourfold. Similar results are described in another report. ... 

The reasons for this effect are uncertain but it seems probable that probenecid successfully competes with aminosalicylic acid for active excretion by the kidney tubules, which results in the increased aminosalicylic acid levels. 

Another possible approach to prolonging the effects of antimalarial drugs is to delay excretion by partially blocking the activity of the excretory mechanism [2]. In the case of rapidly excreted drugs such as peniciUin and the -aminosalicylates, excretion can be delayed by concomitant administration of compounds such as probenecid and -(benzylsulfonamido)benzoic acid which block the excretory mechanism in the renal tubules. However, no compounds are known which delay the excretion of antimalarial drugs, and this approach appears least likely to achieve success. 

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