phenytoin + probenecid

Phenytoin + probenecid is a combination of two small molecule drugs used together to optimize the management of certain medical conditions, primarily epilepsy and gout. Phenytoin is an antiepileptic drug that stabilizes neuronal membranes by selectively inhibiting voltage-gated sodium channels in the brain, thereby reducing seizure activity[4][8]. Probenecid is a uricosuric agent that increases the excretion of uric acid by inhibiting its reabsorption in the renal tubules; it also inhibits renal tubular secretion of various organic acids, including some drugs such as phenytoin[1][2][7]. When administered together, probenecid can increase plasma concentrations of phenytoin by reducing its renal clearance. This pharmacokinetic interaction may be leveraged to maintain therapeutic levels of phenytoin or reduce dosing requirements. The combination does not have a unique brand name and is typically prescribed when clinically indicated for patients requiring both seizure control (phenytoin) and enhanced drug exposure or uricosuria (probenecid).