Penicillin G, 5 million units IV initial dose, then 2.5 million units IV every 4 hours until delivery
May 2020 - Penicillin G on backorder and ampicillin IV in short supply. Use cefazolin 2 g IV initial dose, then 1 g every 8 hours until delivery as the alternative.
An adequate duration of IAP is defined as antibiotic given greater than or equal to 4 hours before delivery.
Penicillin has a narrower spectrum of antimicrobial activity and therefore might be less likely to select for resistant organisms than ampicillin.