Azithromycin Versus Erythromycin For Preterm Prelabor Rupture of Membranes

Azithromycin Versus Erythromycin For Preterm Prelabor Rupture of Membranes: A Randomized Controlled Trial

Aim 1. To examine the latency period according to antibiotic regimens (erythromycin iv for two days followed by orally for 5 days vs. azithromycin iv for 2 days followed by 5 days orally).

Aim 2. To examine the latency period according to races stratified by antibiotic regimens.

Aim 3: To examine if there is a difference in neonatal morbidity and mortality stratified by antibiotic regimen.

Significant differences exist in the pharmacokinetics and pharmacodynamics pathways of macrolide antibiotics between different races and ethnicities. Erythromycin compared to azithromycin interacts with more proteins and is likely affected by genetic variation. Therefore, the investigators hypothesize that the optimal latency antibiotic regimens for PPROM could potentially differ between races.

Due to the paucity of data regarding the use of an azithromycin regimen for latency antibiotics, the Eastern Virginia Medical School MFM team uses an erythromycin regimen even though azithromycin requires less frequent dosing, has lower rates of side effects, and is more cost effective. The Center for Maternal and Child Health Equity at Eastern Virginia Medical School was developed to address health disparities for mothers and their children, and the investigator team is committed to working with the center to address this research gap regarding latency antibiotic use in PPROM.

The aim is to determine the optimal antibiotic regimen for women with PPROM. The hypothesis to be tested are 1) The antibiotic regimen with azithromycin (iv for 2 days followed by 5 days orally) is associated with a longer latency period compared to the antibiotic regimen with erythromycin, and 2) The antibiotic regimen with azithromycin reduces disparity in latency period compared to the antibiotic regimen with erythromycin.

Inclusion Criteria:

• Singleton pregnancy
• PPROM from 22 weeks 0 days to 31 weeks 6 days at Sentara Norfolk General Hospital
• Membrane rupture within 36 hours of randomization, cervical dilation 3 cm or less, and 4 or fewer contractions in the 60-minutes monitoring before randomization

Exclusion Criteria:

• Non-reassuring fetal heart tracing
• Vaginal bleeding
• Indications for delivery
• Received any antibiotic therapy within 7 days other than initiation of Ampicillin treatment as part of latency antibiotics prior to transfer to Sentara Norfolk General Hospital
• Allergy to penicillin, erythromycin, or azithromycin