What is piperacillin/tazobactam sodium-injection, and how does it work (mechanism of action)?

Zosyn is an injectable combination of two antibiotics, piperacillin and tazobactam, with broad spectrum activity against an extended range of bacterial species. Piperacillin is an extended-spectrum penicillin antibiotic, but it can be destroyed by an enzyme produced by bacteria called beta lactamase. Tazobactam inhibits beta lactamase and prevents the destruction of piperacillin. Therefore, tazobactam is given with piperacillin to enhance the activity of piperacillin in eradicating bacterial infections.

Piperacillin kills bacteria by inhibiting the synthesis of bacterial cell walls. It binds preferentially to specific penicillin-binding proteins (PBPs) located inside bacterial cell walls. PBPs vary among bacterial species, and thus susceptibility to piperacillin depends on the ability of piperacillin to bind to each species' specific PBPs.

In-vitro studies of piperacillin and tazobactam have shown that the combination has activity against a variety of gram-positive and gram-negative aerobic and anaerobic bacteria.

Susceptible bacteria include:

• Aerobic and facultative gram-positive microorganisms: Staphylococcus aureus
• Aerobic and facultative gram-negative microorganisms: Acinetobacter baumannii, Escherichia coli, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa
• Gram-negative anaerobes: Bacteroides fragilis group (B.fragilis, B. ovatus, B. thetaiotaomicron, and B. vulgatus)
• Piperacillin and tazobactam was approved by the US Food and Drug Administration (FDA) in October 1993.

What brand names are available for piperacillin/tazobactam sodium-injection?

Zosyn

Is piperacillin/tazobactam sodium-injection available as a generic drug?

GENERIC AVAILABLE: Yes

Do I need a prescription for piperacillin/tazobactam sodium-injection?

Yes

What are the side effects of piperacillin/tazobactam sodium-injection?

Common side effects associated with piperacillin/tazobactam include:

• diarrhea,
• headache,
• constipation,
• nausea,
• difficulty sleeping,
• rash,
• vomiting,
• upset stomach,
• itching,
• stool changes,
• fever,
• agitation,
• Candida (oral [thrush] or genital yeast infeciton),
• high blood pressure,
• dizziness,
• stomach pain,
• chest pain,
• edema,
• anxiety,
• rhinitis, and
• shortness of breath.

Rare side effects occurring with a frequency of less than 1% are:

• agranulocytosis,
• hypersensitivity type reactions,
• anemia,
• canker sores,
• atrial fibrillation,
• bradycardia,
• cardiac arrest,
• cardiac arrhythmia,
• heart failure, and
• Clostridium difficile associated diarrhea.

Which drugs or supplements interact with piperacillin/tazobactam sodium-injection?

• Probenecid may inhibit the renal tubular secretion (elimination via the kidneys) of piperacillin/tazobactam. This may cause higher, prolonged blood levels of piperacillin/tazobactam. The half-life of piperacillin is prolonged by 21% and the half-life of tazobactam by 71%.
• Piperacillin/tazobactam may inhibit platelet aggregation (formation of a blood clot) which may increase the risk for bleeding. Co-administration with blood thinning agents such as warfarin (Coumadin) requires close monitoring for signs or symptoms of bleeding.
• Piperacillin/tazobactam may prolong the neuromuscular blockade of vecuronium (Norcuron).
• Piperacillin/tazobactam may decrease the renal (kidney) elimination of methotrexate (Trexall). Patients on concurrent therapy with methotrexate should be monitored frequently for signs or symptoms of methotrexate toxicity.

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