Interactions between benemid(probenecid) and Neggram (nalidixic acid)
probenecid and nalidixic acid (Moderate Drug-Drug)
GENERALLY AVOID: Coadministration with probenecid may reduce the efficacy of nalidixic acid in the treatment of urinary tract infections while increasing the risk of systemic side effects. The mechanism is probenecid inhibition of the urinary excretion of nalidixic acid via renal tubular secretion, resulting in decreased antibiotic concentration in the urine and increased concentration in the plasma. In a study consisting of two healthy volunteers, coadministration of a single 500 mg dose of nalidixic acid with a single 500 mg dose of probenecid resulted in a threefold increase in peak serum nalidixic acid levels at 8 hours postdose compared to administration of nalidixic acid alone. High plasma levels of nalidixic acid has been associated with metabolic acidosis and may cause central nervous system adverse effects such as drowsiness, weakness, dizziness, vertigo, visual disturbances, convulsions, increased intracranial pressure, and toxic psychosis.
MANAGEMENT: Alternatives to nalidixic acid should preferably be considered for the treatment of urinary tract infections in patients receiving probenecid. Nitrofurantoin and sulfamethoxazole-trimethoprim have not been reported to interact with probenecid and may be suitable choices depending on organism susceptibility.
