TIRONEM undergoes little to no Cytochrome P450 (CYP450) mediated metabolism. Based on in vitro studies it is not expected that TIRONEM will inhibit or induce the activities of CYP450. Therefore, no CYP450-related drug interactions are to be expected.
Carbapenem antibacterial agents may reduce serum valproic acid concentrations. Serum concentrations of valproic acid should be monitored if TIRONEM is administered concomitantly with valproic acid.
Probenecid competes with TIRONEM for renal tubular secretion and reduces the renal clearance of TIRONEM. In an interaction study, the mean TIRONEM AUC increased by 75% following co-administration with probenecid. Therefore, co-administration of probenecid with TIRONEM is not recommended. An interaction with other drugs eliminated by renal tubular secretion can not be excluded.