From the Guidelines
Azithromycin can be used as an alternative to erythromycin in the management of preterm premature rupture of membranes (PROM) when erythromycin is not available, given its potential benefits and lack of evidence showing decreased efficacy 1. The current standard antibiotic regimen for preterm PROM typically consists of ampicillin and erythromycin, but azithromycin may be considered as a substitute, particularly for its once-daily dosing which can improve patient compliance. Key considerations in the management of preterm PROM include prolonging the latency period, reducing maternal and neonatal infections, and improving neonatal outcomes by targeting potential pathogens such as Group B Streptococcus, E. coli, and genital mycoplasmas. Some studies suggest that antibiotics can be beneficial in the management of previable and periviable preterm prelabor rupture of membranes, with recommendations for their use at or after 24 weeks of gestation 1. However, the optimal antibiotic type, dose, and timing of administration after previable and periviable PPROM are unknown, and clinical practice may vary significantly 1. Given the lack of clear evidence on the benefits of specific antibiotics in this context, the decision to use azithromycin or any other antibiotic should be based on individual patient circumstances and the potential risks and benefits of treatment 1. In general, antibiotic stewardship is crucial to avoid prolonged or repeated antibiotic courses beyond what is necessary for the management of PPROM at later gestational ages. The role of azithromycin in managing preterm PROM should be considered within the broader context of maternal and fetal risks and benefits, and its use should be guided by the most recent and highest-quality evidence available, taking into account factors such as patient compliance, potential side effects, and the specific clinical scenario 1.
From the Research
Role of Azithromycin in Preterm PROM
- Azithromycin is used as an alternative to erythromycin in the management of preterm premature rupture of membranes (PROM) due to its ease of administration, better side effect profile, and decreased cost 2.
- A study comparing azithromycin and roxithromycin found that azithromycin results in a longer latency period in the setting of preterm PROM at 24-34 weeks of gestation 3.
- The optimal dosing regimen of azithromycin for preterm PROM is still being researched, with some studies suggesting that extended administration may be beneficial 4, 5.
- A randomized controlled trial found that a higher dose of azithromycin was associated with better maternal and neonatal outcomes, including a longer latency period and lower rates of postpartum endometritis and respiratory distress syndrome 5.
- Another study found that daily dosing of azithromycin maintains higher amniotic fluid concentrations and more consistently greater than common minimum inhibitory concentrations over 8 days compared with a single dose 6.
Comparison of Azithromycin Regimens
- A study comparing different azithromycin regimens found that there was no statistical difference in median latency time between azithromycin 1 day, azithromycin 5 days, azithromycin 7 days, and erythromycin groups 2.
- However, another study found that extended azithromycin administration was associated with increased latency, without any effect on other maternal or neonatal outcomes 4.
- A randomized clinical trial found that azithromycin 1000 mg PO once was associated with a longer latency period and better maternal and neonatal outcomes compared to azithromycin 500 mg PO once, followed by azithromycin 250 mg PO daily for four days 5.
Azithromycin Concentrations
- A study found that daily dosing of azithromycin maintains higher amniotic fluid concentrations and more consistently greater than common minimum inhibitory concentrations over 8 days compared with a single dose 6.
- The study also found that plasma azithromycin concentrations declined and were virtually undetectable in the single-dose group, whereas trough plasma levels in the daily dosing group remained elevated 6.