Standardisation of ready-to-use intravenous antimicrobial preparation in a paediatric hospital-at-home unit

Outpatient parenteral antimicrobial therapy (OPAT) in paediatric hospital-at-home (HAH) units is expanding. Standardisation of ready-to-use presentations increases safety, reduces variability, and facilitates logistics, particularly in paediatrics, where administration volumes, maximum concentrations, and infusion times strongly condition preparation.

To standardise the antimicrobials used in a paediatric HAH unit by defining preparation, final container selection, and storage, based on the available evidence on physicochemical and microbiological stability, while considering administration criteria specific to the paediatric setting.

Antimicrobials included in the hospital's OPAT protocol were selected. Administration systems and consumables were reviewed, prioritising syringes and low-adsorption plastic materials. Maximum concentrations and infusion times recommended in paediatrics were compiled. Physicochemical stability was established through a literature review, selecting studies with comparable conditions (diluent, concentration, temperature, photoprotection, and primary container material) and assays that had evaluated active ingredient degradation; a content deviation of ≤10% was considered acceptable. Microbiological stability was estimated using the risk matrix for sterile preparations from the Good Preparation Practice Guide for Hospital Pharmacy Services, considering aseptic compounding in a cleanroom using a Class II biological safety cabinet and subsequent home storage.

Sixteen antimicrobials were standardised (acyclovir, amikacin, ampicillin, cefazolin, cefepime, ceftazidime, ceftriaxone, cefuroxime, cidofovir, clindamycin, ganciclovir, imipenem/cilastatin, meropenem, piperacillin/tazobactam, tobramycin, and vancomycin). A fixed diluent volume and filling into syringes were prioritised; bags were used when the volume exceeded 60 mL. For each drug, diluent, material, temperature, photoprotection, and maximum in-use time were defined, integrating physicochemical stability evidence and adopting a conservative approach for microbiological use due to uncontrolled home refrigeration.

This study supports a more uniform and safer OPAT practice in paediatric HAH units and provides an operational basis for protocol implementation and future evaluation, combining stability evidence for compounded preparations with paediatric administration requirements.