From the Guidelines
Linezolid should be used with caution during pregnancy and only when the potential benefits outweigh the risks, as it is classified as FDA pregnancy category C. This classification indicates that animal studies have shown adverse effects on the fetus, but there are no adequate well-controlled studies in humans 1. The limited human data available regarding safety is a main concern with linezolid use during pregnancy. Linezolid works by inhibiting bacterial protein synthesis by binding to the 23S ribosomal RNA of the 50S subunit, which is effective against resistant gram-positive bacteria including MRSA and VRE.
Some key points to consider when using linezolid during pregnancy include:
- Potential side effects that should be monitored, such as myelosuppression (particularly with treatment longer than 2 weeks), serotonin syndrome if combined with serotonergic medications, and peripheral and optic neuropathy with prolonged use 1.
- Regular blood counts should be monitored weekly during treatment to minimize the risk of adverse effects.
- Alternative antibiotics with better established safety profiles in pregnancy should be considered first when appropriate based on the infection and susceptibility testing 1.
- The typical adult dosage is 600 mg orally or intravenously every 12 hours for 10-14 days, depending on the infection being treated.
It is essential to weigh the potential benefits and risks of linezolid use during pregnancy, considering the limited human data available and the potential for adverse effects on the fetus. The decision to use linezolid during pregnancy should be made on a case-by-case basis, taking into account the severity of the infection and the potential risks and benefits of treatment.
From the FDA Drug Label
Linezolid was not teratogenic in mice, rats, or rabbits at exposure levels 6.5-fold (in mice), equivalent to (in rats), or 0. 06-fold (in rabbits) the expected human exposure level, based on AUCs. However, embryo and fetal toxicities were seen (see Non-teratogenic Effects). There are no adequate and well-controlled studies in pregnant women. ZYVOX should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus Non-teratogenic Effects In mice, embryo and fetal toxicities were seen only at doses that caused maternal toxicity (clinical signs and reduced body weight gain). When female rats were treated with 50 mg/kg/day (approximately equivalent to the estimated human exposure based on AUCs) of linezolid during pregnancy and lactation, survival of pups was decreased on postnatal days 1 to 4.
Key Points:
- Pregnancy Category C: Linezolid should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
- Embryo and Fetal Toxicities: Observed in animal studies, but only at doses that caused maternal toxicity.
- Lack of Human Studies: No adequate and well-controlled studies in pregnant women.
- Use with Caution: Linezolid should be used with caution in pregnant women, and only if the potential benefit outweighs the potential risk to the fetus 2.
From the Research
Linezolid in Pregnancy
There are no research papers to assist in answering this question. The provided studies do not mention the use of linezolid in pregnancy.
Available Information on Linezolid
- Linezolid is an antibiotic that inhibits bacterial protein synthesis through binding to rRNA 3
- It is used to treat infections caused by vancomycin-resistant Enterococcus faecium, hospital-acquired pneumonia caused by Staphylococcus aureus, and other infections 3
- Linezolid has been compared to other antibiotics, such as clindamycin and vancomycin, in the treatment of various infections 4, 5
- The safety and tolerability of linezolid have been reviewed, but not specifically in the context of pregnancy 6
- Linezolid has been discussed in the context of lactation, with information on its excretion into breast milk and potential risks to nursing infants 7