Is Zosyn (piperacillin/tazobactam) contraindicated in pregnant women?

From the Guidelines

Zosyn (piperacillin/tazobactam) is not contraindicated in pregnant women and can be used when clinically indicated during pregnancy. According to the most recent evidence from the European Respiratory Journal in 2020 1, piperacillin/tazobactam is classified as compatible with pregnancy, with no teratogenic effects in animal studies and no cases of congenital defects reported in humans. The medication is present in breast milk, but it has low oral bioavailability, making it unlikely to cause harm to the infant.

Key Considerations

• The medication has been used safely to treat serious infections during pregnancy, including pyelonephritis, intra-abdominal infections, and sepsis.
• The standard adult dosing of 3.375g IV every 6 hours or 4.5g IV every 8 hours (with adjustments for renal function) applies during pregnancy as well.
• When treating infections during pregnancy, the benefits of controlling the infection typically outweigh the theoretical risks of the medication.
• Healthcare providers should consider the severity of the infection, the patient's clinical status, and alternative antibiotic options when prescribing Zosyn during pregnancy.

Clinical Decision-Making

As with any medication during pregnancy, Zosyn should be used only when clearly needed and when the potential benefits justify the potential risks to the fetus. The decision to use Zosyn during pregnancy should be made on a case-by-case basis, taking into account the individual patient's circumstances and the severity of the infection being treated. According to the evidence 1, all penicillins, including piperacillin/tazobactam, are considered low risk in pregnancy, making Zosyn a viable option for treating infections in pregnant women.

From the FDA Drug Label

1. 1 Pregnancy Risk Summary Piperacillin and tazobactam cross the placenta in humans. However, there are insufficient data with piperacillin and/or tazobactam in pregnant women to inform a drug-associated risk for major birth defects and miscarriage

Zosyn (piperacillin/tazobactam) is not explicitly contraindicated in pregnant women. However, there are insufficient data to inform a drug-associated risk for major birth defects and miscarriage.

• The drug label recommends considering the benefits and risks of using piperacillin and tazobactam during pregnancy, but it does not provide a clear contraindication.
• Fetotoxicity and maternal toxicity were observed in animal studies, but the clinical significance of these findings is unclear.
• The decision to use Zosyn in pregnant women should be made on a case-by-case basis, taking into account the potential benefits and risks 2.

From the Research

Zosyn (Piperacillin/Tazobactam) in Pregnant Women

• Zosyn (piperacillin/tazobactam) is not contraindicated in pregnant women, but its use is considered to be moderately safe (pregnancy category B) for the human embryo-foetus 3.
• A study found that piperacillin/tazobactam can cause adverse reactions such as bone marrow suppression, fever, leucopenia, neutropenia, and thrombocytopenia in pregnant women, although these reactions are rare and reversible upon discontinuation of the drug 3.
• Another study investigated the pharmacokinetics and transplacental transfer of piperacillin/tazobactam in pregnant women and found that the combination was safe and well-tolerated, with significant transplacental transfer of the drug 4.
• The safety and efficacy of piperacillin/tazobactam have been established in various clinical trials, including those involving pregnant women, although the drug's use in pregnancy should be carefully monitored due to potential adverse effects 5, 6.
• Reformulation of Zosyn has improved its compatibility and coadministration with other drugs, including lactated Ringer's solutions and selected aminoglycosides, which may be beneficial in pregnant women requiring treatment with multiple medications 7.