Antimicrobial formulary and restrictions An antimicrobial formulary is a simplified list of available antimicrobials within a hospital, potentially including: accepted indications for use, dosing schedules, drug interactions and side effects. The formulary should include a sub-set of restricted antimicrobials. The use of these restricted antimicrobials requires strict monitoring and adherence to the antimicrobial prescribing policy of the hospital. The WHO AWaRe classification of antibiotics could be used as the base of an AMS restriction policy, with those falling into the Watch and Reserve groups forming targets for AMS activities. Auditing compliance with the antimicrobial formulary is important to ensure that the restriction polices are being adhered to. improved procurement processes; easier inventory management; decreased healthcare costs; reduced adverse drug reactions; and improved patient care. Antimicrobials will be selected on their ability to treat the relevant infectious diseases of the country or region. The formulary should be consistent with any national formulary or approved standard infection treatment guidelines. The formulary should be reviewed and revised periodically. Combination/fixed-dose antimicrobials should only be used in specific proven infections (e.g., tuberculosis or HIV). The ability to prescribe antimicrobials is restricted to only those practitioners with appropriate prescribing skills. acceptable data on safety, pharmacological action, adverse drug reactions, and drug interactions; reasons why this is superior to current formulary-listed antimicrobial(s); scientific evidence and literature to support its addition; updated clinical guidelines or treatment pathways; altered country or hospital infection patterns and antibiogram; acceptable cost-efficiency; and approved and quality source of supply. the antimicrobial is no longer used; recent data on lack of safety, efficacy, quality, etc., has become available; and the antimicrobial does not meet the requirements for cost-effectiveness, if an acceptable alternative is identified. Review of current stock on hand and duration of expected use before stock runs out. Pharmacy departments are often well placed to do this. Communicate possible stock shortage situations to stakeholders, including medical staff (ID specialists if available), early so that they can prepare. Conduct clinical review and provide recommendations for alternatives. This may be based on indication and severity of infection. Alternatives can include using other strengths and dose forms, and other antimicrobials with a similar required spectrum of activity; and undertaking early intravenous-to-oral switches. Consider the practical implications of the alternatives recommended, including storage, quantity and cost. Options to respond to shortages: use emergency stock; procure stock through other means or access schemes; use an alternative brand; use a different dose, form or strength; use an alternative medicine of equal efficacy; use second- or third-line medicines; and borrow stock from another hospital or pharmacy. Who is currently prescribing the drug (what wards or units)? For which indications is it being used? Is that use appropriate? A brief audit may be helpful to better understand this. E.g., look back over 20 or 30 prescriptions of that drug. Can we rationalise its use? Is earlier intravenous-to-oral switch possible, especially for agents with high oral bioavailability? Review durations of use: are prescribers using unnecessarily prolonged courses? Is there any unnecessary use, e.g., any cases of prolonged post-operative antibiotic prophylaxis that is not necessary? Are there other appropriate alternative drugs, and are they in stock? E.g., for cefazolin, use cefalotin. E.g., for ampicillin, use amoxicillin. Are there indications for which there is no appropriate alternative (i.e., we want to reserve the drug for these high-risk conditions)? E.g., intravenous acyclovir for presumed or proven encephalitis. E.g., intravenous benzylpenicillin for neurosyphilis. E.g., gentamicin for enterococcal endocarditis. Can we recommend appropriate replacements or combinations of replacements that might vary by indication? E.g., for metronidazole shortage: alternative agents to treat anaerobic infections might include clindamycin, amoxicillin-clavulanate or piperacillin-tazobactam. A clear communication plan is key to managing a shortage. A written poster can be very useful so that the plan is clear. Examples of these fact sheets can be found on our website here . Talk to executive. Talk to clinical leaders and senior doctors. Talk to nurse unit managers. Ask them to communicate information to their teams at ward and unit meetings. Where is the drug stocked? Can we remove the drug from that location and put the alternative drug (and the information about the issue) in that location?

Think about wards, emergency department, theatres, etc. limiting the number of non-formulary antimicrobials to only those essential for treatment; limiting access to only those prescribers who are appropriately qualified to be requesting these antimicrobials; and keeping a register of all non-formulary medicines used and reviewing these at the DTC meetings. dosage schedule and formulations; and indications for approved use, including rational drug use information (e.g., IV-to-oral switch, de-escalation, etc.). contraindications, adverse drug reactions, drug interactions, etc.; prescribing information for children and the elderly, and for renal failure; storage guidelines; instructions and warnings on preparation and administration; and specific guidelines on the use and administration of the antimicrobial. regulation category; brand names and synonyms; labelling information; and patient- and carer-counselling information. Government of South Australia. SA Health medicines formulary , Government of South Australia. spectrum of activity of the antimicrobial (last-line agent); cost of the antimicrobial; and potential for toxicity. by a particular specialty or unit of the hospital; for particular pathogens or conditions; for situations when the resistance profile of the organism precludes other options; for situations where other options are contraindicated (allergies, drug intolerance, drug interactions, etc.); and where there has been demonstrated treatment failure with other options. a statement from the executive outlining support for the policy and how all prescribers are required to abide by the restriction protocols; how medical officers should obtain antimicrobial approvals prior to prescribing restricted antimicrobials; any relevant drug order forms; pharmacists' responsibility to check that an approval has been obtained prior to dispensing the antimicrobial; nurses' responsibility to check that an approval has been obtained prior to administering the antimicrobial; and what to do if there is no approval: who to contact; whether the first dose can still be dispensed and administered; and whether there is a 24-48 hour grace period to cover out-of-hours prescribing. decreased quantity of restricted antimicrobials prescribed; reduced drug expenditure; decreased lengths of stay; improved resistance profiles of certain local pathogens; and more appropriate empirical antimicrobial choices. how many requests for approvals to use restricted antimicrobial are received; how many prescriptions for restricted antimicrobials received approval versus how many were rejected; and how many restricted antimicrobials were dispensed and administered without an official approval. start-date for the prescription; name of the antimicrobial (this should ideally be the generic name, not the trade name); intended route of administration; required frequency of administration; printed name of the prescriber; and signature of the prescriber. the indication for the antimicrobial; the intended stop-date, or a review-date for the antimicrobial; if not compliant with the recommended guidelines, a justified reason for any deviation; and any need for therapeutic drug monitoring. Implementing antimicrobial stewardship Policy drivers for AMS Fundamentals of AMS Core elements of AMS Governance and policy Antimicrobial formulary and restrictions Clinical microbiology laboratory Information technology for AMS Getting started Behaviour change Guidelines and clinical pathways Pre-prescription review Post-prescription review Point-of-care interventions AMS program evaluation Feedback and communication © The University of Melbourne 2025