What’s New: Antibiotic December 2025

• Perinatal infections
• Surgical prophylaxis
• Skin and soft tissue infections
• Traumatic wounds
• Summary tables

Perinatal infections

• The combination of amoxicillin (or ampicillin) plus a macrolide continues to be recommended for prophylaxis for preterm prelabour rupture of membranes (PPROM); azithromycin is now an alternative to erythromycin. New alternatives to penicillin are included to support combination prophylaxis in patients with penicillin hypersensitivity.
• Metronidazole is now included in the first line regimen for intra-amniotic infection to target a broader range of anaerobic bacteria.
• The Septic abortion topic has been expanded to now include drug recommendations for treatment of nonsevere and severe septic abortion and advice on modification and duration of therapy.

Surgical prophylaxis

• A cefazolin dose of 3 g is now recommended for surgical prophylaxis in adults who weigh 120 kg or more and have a glomerular filtration rate more than 40 mL/min.
• Cefazolin is now recommended for surgical prophylaxis in patients with a history of severe immediate penicillin hypersensitivity who are undergoing a procedure in hospital.
• Aminoglycoside dosing for surgical prophylaxis has been completely revised, with updated adult and paediatric gentamicin dosage regimens and tobramycin now recommended as an alternative.
• A new figure listing the contraindications and precautions to aminoglycoside use for surgical prophylaxis is included in Principles of surgical antibiotic prophylaxis.
• A vancomycin dose cap of 2 g has been added to surgical prophylaxis and endocarditis prophylaxis drug recommendations.
• Evidence on alternative routes of administration (other than oral, intramuscular and intravenous) for surgical prophylaxis is limited. The use of an absorbable, antibiotic-eluting envelope is supported by randomised controlled trial data for selected cardiac implantable electronic device (CIED) procedures in patients at high risk of CIED infection. Other routes of administration (eg topical antimicrobials, intraosseous antibiotics, antibiotic-soaked grafts) are not currently recommended because of either a lack of demonstrated benefit or insufficient evidence.
• A new topic on Surgical prophylaxis for emergency exploratory laparotomy provides guidance on indications for prophylaxis, recommended antibiotic regimens and other key considerations.
• The vascular procedures covered in the guidelines have been expanded to include endovascular and hybrid procedures commonly performed in modern vascular surgical practice.

Skin and soft tissue infections

• Guidance on lactational mastitis has been expanded and includes:
  • clearer diagnostic criteria to distinguish it from localised breast inflammation
  • comprehensive nonantibiotic management advice
  • intravenous antibiotic regimens
  • advice for patients not responding to treatment, including when and how to collect a sample of expressed breastmilk for culture.
• Choice of empirical antibiotic therapy for surgical site infections now depends on the surgical wound stratification and the risk of methicillin-resistant Staphylococcus aureus (MRSA) infection.
 

Traumatic wounds

• To improve usability, the traumatic wound topics have been significantly restructured. To find the right traumatic wound topic, see Approach to managing traumatic wounds.
• Trimethoprim+sulfamethoxazole is the oral antibiotic recommended for all water-immersed traumatic wound infections; choice no longer depends on whether the water was fresh, brackish or salt. Metronidazole should still be included in the treatment regimen for infected wounds immersed in soil- or sewage-contaminated water.

Summary tables

• All Surgical antibiotic prophylaxis: Therapeutic Guidelines summary tables have been updated to reflect revised surgical prophylaxis recommendations. New summary tables are also available for emergency exploratory laparotomy and ophthalmic surgery .
• The Antibiotic prescribing in primary care: Therapeutic Guidelines summary table has been updated to reflect changes in guidance for lactational mastitis and bite wounds, including clenched-fist injuries.