To promote best evidence based practice in prescribing antimicrobials in order to:

• Optimise the treatment of infections and improve patient outcomes
• Minimise inappropriate antibiotic use and the development of resistance
• Minimise antibiotic related adverse events
• Ensure cost effective prescribing.

These goals are highlighted in the Children’s Health Antimicrobial Prescribing and Management procedure.

• To put in place antimicrobial prescribing guidelines
• To put in place an antimicrobial formulary and approval system
• To conduct antimicrobial prescribing audit with feedback to prescribers
• To liaise with microbiology to:
  • Monitor resistance trends
  • Ensure susceptibility reporting is consistent with prescribing guidelines and the formulary
  • Produce cumulative antibiograms that can inform potential changes to prescribing guidelines
• To monitor antimicrobial dispensing data and the use of non-formulary antimicrobials
• Provide education relating to antimicrobial prescribing.

Infections with antibiotic-resistant organisms are increasingly common in the community as well as in healthcare and are associated with increased morbidity and mortality. Some examples are:

VRE (Vancomycin-resistant E. Faecium)

VRE is strongly selected for by the use of ceftriaxone and vancomycin.

An outbreak could result in high financial cost of managing such an outbreak. The emotional, psychological and social impact on children in hospital due to infectious isolation is significant.

MRSA

About 19% of Staph aureus bacteraemias from the Queensland community are now MRSA. In 2001, it was less than 1%.

ESBL (Extended Spectrum Beta-Lactamase producing)E. coli

Is an increasingly common cause of community-associated UTI and urosepsis, and may require IV antibiotics as there are no effective oral options.

ESBL E. coli is strongly selected for by the use of ceftriaxone.

NDM-1

NDM-1 is an antibiotic resistance gene found in gram-negative bacteria such as E. coli and Pseudomonas sp.

It confers resistance to carbapenems (e.g. meropenem), which are usually reserved as last-line agents in serious or antibiotic-resistant infections. It was first described in 2008. It has since spread globally, including cases identified in Australia.

There are few new antibiotics in the development pipeline and none in new classes effective against gram-negative bacteria.

Changes in institutional prescribing practices can influence local resistance rates and it has been proven that by minimising the unnecessary use of antibiotics, the progression towards more resistance can be slowed, hopefully until either new antimicrobials or other new approaches such as vaccines can be developed.

A number of bacterial and viral diseases are self-limiting and do not benefit from antibiotics. Prescribing of antimicrobial therapy in such cases may expose the patient to undue risks and may contribute to the development of resistance.

Choose antimicrobials based on factors such as:

• Suspected / known infecting organism/s
• Spectrum, safety profile and cost of available antimicrobials
• Previous clinical experience
• Potential for selection of resistant organisms
• Risk of superinfection
• Known drug allergy details
• Interactions with other drugs.

These factors should be considered in light of the clinical condition of the patient.

The aim of prophylaxis in the surgical setting is to produce adequate tissue and plasma levels at the time contamination is most likely which is during the procedure.

Perioperative considerations

Empirical antimicrobial therapy should be prescribed based on likely clinical diagnosis, suspected aetiology and local susceptibility test results. Where possible, such information has been incorporated into these guidelines. It is important, where possible, to:

• Obtain a specimen BEFORE commencing antimicrobial therapy
• Use the results of Gram stain or direct detection methods to prescribe specific therapy before culture results are available.

Review of empirical antimicrobial prescribing should be made in light of available culture results. This information, considered in the context of the clinical condition of the patient, should be used to prescribe the most efficacious, cost-effective agent with the lowest incidence of toxicity and the narrowest spectrum of activity. Such practice will help to reduce the problems associated with broad-spectrum therapy i.e. selection of resistant microorganisms and superinfection.

The dose of an antibiotic varies according to a number of factors including age, weight, hepatic and renal function, and the severity of infection. It is important to optimize antimicrobial dosing according to severity of infection, resistance patterns (minimum inhibitory concentrations) and Therapeutic drug monitoring (TDM).

Consult your Ward or Unit Clinical Pharmacist for further assistance with interpretation of antimicrobial levels.

An indication and a stop/review date or intended duration should be specified on the medication chart at the point of prescribing any antimicrobial agent (when an order for antimicrobial therapy is made).

The National Inpatient Medication Chart should be annotated with the following information:

• The Indication for Antimicrobial Therapy
• The Intended Stop/Review Date for Antimicrobial Therapy
• The chart should be Numbered with the Days of Therapy to assist with review
• The words “ID approved” and the unique ID Approval number provided by the Approving ID Physician or Microbiologist.

The Outpatient prescription should be annotated with the following information:

• The Indication for Antimicrobial Therapy
• The Intended duration for Antimicrobial Therapy
• The PBS restriction/ authority number (If required)
• The unique ID Approval number provided by the Approving ID Physician or Microbiologist, if applicable.

Initially, giving antimicrobials by the intravenous (IV) route may be preferable in severe infection. However in the majority of patients who are clinically improved and adequately absorbing oral drugs, administration can be switched to the oral route after 48 hours of IV therapy. This is known as the IV to oral switch.

For more information, see CHQ Antimicrobial Treatment: Early Intravenous to Oral switch – Paediatric guideline.