Tazovex Drug Interactions

Concurrent administration of probenecid and piperacillin and tazobactam for injection produced a longer half-life and lower renal clearance for both piperacillin and tazobactam. However, peak plasma concentrations of neither drug are affected. No kinetic interaction is found between piperacillin and tazobactam for injection and vancomycin.
Concurrent administration of piperacillin and tobramycin in patients with severe renal dysfunction (ie chronic hemodialysis patients) has been reported to reduce the elimination half life and significantly increase the total body clearance of tobramycin.
The alteration of tobramycin pharmacokinetics in patients with mild to moderate renal dysfunction who are taking piperacillin concomitantly is unknown. However, reports suggest that the aminoglycoside inactivation in patients concomitantly taking an amino glycoside with a broad spectrum beta-lactam penicillin is only clinically significant in patients with several renal dysfunction.
The inactivation of aminoglycosides in the presence of penicillin class drugs has been recognized. It has been postulated that penicillin-amino glycoside complexes form; these complexes are microbiologically inactive and of unknown toxicity.
Piperacillin when used concomitantly with vecuronium has been implicated in the prolongation of the neuromuscular blockade of vecuronium. Piperacillin and tazobactam for injection (piperacillin/tazobactam) could produce the same phenomenon if given along with vecuronium. Due to their similar mechanism of action, it is expected that the neuromuscular blockade produced by any of the non-depolarizing muscle relaxants could be prolonged in the presence of piperacillin.
Piperacillin may reduce the excretion of methotrexate, therefore, serum levels of methotrexate should be monitored in patients to avoid drug toxicity.
If piperacillin and tazobactam for injection is used concurrently with another antibiotic, especially an amino glycoside, the drug must not be mixed in intravenous solution or administered concurrently due to physical incompatibility.
During simultaneous administration of high doses of heparin, oral anticoagulants and other drugs that may affect the blood coagulation system and/or the thrombocyte function, the coagulation parameters should be tested more frequently and monitored regularly.
Effects on Laboratory Tests: As with other penicillin, the administration of piperacillin/tazobactam may result in a false positive reaction for glucose in the urine using a copper-reduction method. It is recommended that glucose tests based on enzymatic glucose oxidase reaction be used.
There have been reports of positive test results using Bio-Rad Laboratories Platelia Aspergillus EIA test in patients receiving piperacillin and tazobactam for injection, who were subsequently found to be free of Aspergillus infection. Cross-reaction with non-Aspergillus polysaccharides and polyfuranoses with Bio-Rad Laboratories Platelia Aspergillus EIA test have been reported. Therefore, positive test results in patients receiving piperacillin and tazobactam for injection should be interpreted cautiously and confirmed by other diagnostic methods.