Interaction between Cefdinir and Probenecid
Moderate Excretion

ID DDInter315 and DDInter1522
Interaction Coadministration with probenecid may increase and prolong the serum concentrations of some cephalosporins. The proposed mechanism is competitive inhibition of renal tubular secretion by probenecid.
Management Although probenecid has been used therapeutically to enhance serum levels of various beta-lactam antibiotics, the potential for increased adverse effects should be considered when probenecid is added to existing cephalosporin therapy, particularly when the latter is given at high dosages or to patients who are elderly or have renal dysfunction. Adjustment of the cephalosporin dosage may be required in accordance with the individual product labeling. For example, cefotaxime dosage should generally not exceed 6 grams/day when administered with probenecid. Probenecid reportedly does not affect the elimination of ceftazidime or ceftriaxone.
References
Alternative for Cefdinir J01D
Alternative for Probenecid M04A

G01A
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Potential Metabolism Interactions

Substrate-Substrate Interaction:If more than one drug is metabolized by the same CYP, it is possible that its metabolism is inhibited because of the competition between the drugs. That means, it can be useful to lower the dosage of the drugs in the drug-cocktail because they remain longer in the organism than in monotherapy.
Inhibitor-Inhibitor Interaction:Combining two or more inhibitors of one CYP, should be compensated by lowering the dosage of these drugs because the metabolism is reduced and the drugs remain longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.
Inhibitor-Substrate Interaction:Combining drugs that have inhibitory effect and are substrates of one particular CYP, should be compensated by lowering the dosage. They rest longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.