Epic Pharmacy Circuit Clinical Newsletter - World Antimicrobial Awareness Week 2021 Special Edition

2021 Edition 3

Spread Awareness, Stop Resistance World Antimicrobial Awareness Week is from 18 - 24 November 2021. It aims to raise awareness of antimicrobial resistance and promote the responsible use of antimicrobials.

clinical initiatives, research and current updates in treatment

Antimicrobial Use and Resistance in Australia (AURA) 2021 Update Megan Kren, Epic Pharmacy Wesley The fourth Australian report on antimicrobial use and resistance in human health (AURA 2021) was recently released by the Australian Commission on Safety and Quality in Health Care, reporting on antimicrobial resistance (AMR) and antimicrobial use (AU) data in Australian health care.

COVID-19 also had a positive effect on AMR with reports of multidrugresistant Shigella species dramatically

decreasing in April 2020 also coinciding with the introduction of COVID-19 restrictions.2

Figure 1: Number of prescriptions for systemic antibiotics (J01) supplied in 2019 and 2020.²

Antimicrobial use drives AMR.1 Growing rates of AMR are a significant threat to many areas of health care, from cancer treatment to surgical interventions.1 The data and reports generated from the AURA report are utilised to improve clinical practice and prevent and contain AMR.2 Several highlights from the report are summarised below:

Positive Impact of Novel Coronavirus (COVID-19)

Figure 2: Number of prescriptions for oral systemic antibiotics typically used for URTI, urinary tract infections, skin infections, and other infections, 2019 and 2020.²

COVID-19 profoundly impacted AU with an average 34% drop in Pharmaceutical Benefits Scheme (PBS) supplied antibiotics in primary care in 2020 (see Figure 1).2 Antibiotics principally used for upper respiratory tract infections (URTI) saw a sharp decline in April 2020, coinciding with the introduction of pandemic controls and remained below pre-pandemic levels for the rest of the year (see Figure 2).2 Importantly, this decline in use was not associated with a drop in primary care visits, suggesting infection prevention and control actions introduced in April resulted in these significant reductions.2 This trend was also reflected internationally.2 Continued on page 2

Hospitals

Community

Antimicrobial resistance

¬ AU in hospitals has increased annually from 2016 (2.5%) to 2019 (2.8%), with no improvement in antimicrobial appropriateness.2 Nearly one-quarter of the prescriptions assessed were found to be inappropriate.2

¬ In 2019, 40.3% of the Australian population had at least one antimicrobial dispensed under the PBS/RPBS; higher than most European countries and Canada.2

Resistance rates in some common pathogens are at levels at which prescribing practice recommendations will need to be reviewed.

¬ The most common indications for inappropriate AU were: • Chronic obstructive pulmonary disease (COPD) (45.8%)2 • Surgical prophylaxis (42.3%)2 • Community-acquired pneumonia (23.7)2 ¬ The 2019 Surgical National Antimicrobial Prescribing Survey reported: • Low rates of compliance with prescribing guidelines for procedural (62.7%) and postprocedural (31.4%) antimicrobial surgical prophylaxis in relation to timing, dosage, and duration of use.3 • Prophylactic use of topical antimicrobials was deemed inappropriate in 75.5% of procedural prophylaxis and 65.2% post-procedural prophylaxis.4 • Marginal improvements were noted in three critical areas:2 - Documentation of indication (84.2%) - Documentation of review or stop date (48.0%) - The proportion of surgical prophylaxis given for greater than 24 hours (30%)

¬ AU is declining in the community, but inappropriate prescribing continues, especially with regards to:2

¬ Resistance to trimethoprim in E. coli is currently at around 25% nationally. This has a potential impact on the treatment of lower urinary tract infections.2

• Increased private prescribing of PBS-restricted ciprofloxacin, particularly concerning considering increasing rates of resistance to ciprofloxacin and other fluoroquinolones to Escherichia coli.

¬ High rates of resistance (>75%) to ciprofloxacin in the Salmonella species causing enteric fever (Salmonella Typhi, Salmonella Paratyphi) confirm these agents should no longer be relied on for empirical therapy.2

• Overprescribing of broadspectrum antimicrobials such as cefalexin and amoxicillinclavulanic acid which have greater potential to promote resistance to multiple drug classes.

¬ Rates of resistance to erythromycin and clindamycin in Streptococcus agalactiae (group B Streptococcus) has steadily increased to around 33% in 2019, meaning that this agent should only be used at delivery for preventing neonatal sepsis if the organism is known to be susceptible after laboratory testing.2

Residential aged care services (RACS) RACS have higher levels of multidrug resistant organisms, putting residents at high risk of infections and colonisations with these pathogens.5 Factors contributing to AMR include:5 ¬ High rates of ‘when required’ and prophylactic prescribing in preference to non-pharmaceutical measures for conditions such as urinary tract and soft tissue and skin infections, increasing the risk for prolonged duration. ¬ Poor documentation of indication, review and stop dates.

References are available on request.

Updated Antimicrobial Stewardship Clinical Standards Sarah Loughrey, Epic Pharmacy St Andrews War Memorial In November 2020, the Australian Commission on Safety and Quality in Health Care released an update to the Antimicrobial Stewardship (AMS) Clinical Care Standard.¹ Implementing the AMS Clinical Care Standard is a requirement for all health service organisations assessed against the National Safety and Quality Health Service Standards.¹ The goals of the AMS Clinical Care Standard are to ensure antimicrobials are used appropriately to optimise patient outcomes, limit harms from adverse effects and reduce

antimicrobial resistance.¹ A key feature of the 2020 update was the addition of the new quality statement 3: Adverse reactions to antimicrobials and it’s corresponding indicator to support local monitoring, 3a: The proportion of patients with an adverse drug reaction to an antimicrobial with comprehensive documentation in the healthcare record.¹ The purpose of introducing this new quality statement is to support the most appropriate antimicrobial prescribing of the narrowest spectrum

agent whilst avoiding harmful adverse effects such as anaphylaxis.¹ The AMS Clinical Care Standard recommends six essential elements be considered by clinicians when documenting and assessing an adverse reaction.¹ (see Figure 3, next page) It is important that any changes made to a patient’s allergy/adverse drug reaction history is communicated with the patient and their regular clinician, and documentation provided, if appropriate.¹

Figure 3:

Essential elements for assessing an adverse reaction to a medicine

reduce the use of more restricted antibiotic resources.2

The essential elements for assessing an adverse reaction are the:

From information to action

¬ Patient's description of the event (what happened to the patient)

Some health facilities are now actively pursuing programs to remove adult patient low-risk penicillin allergies from the patient’s health record.4 This involves directly removing the penicillin allergy from the patient record (or delabeled), after assessment of the allergy or following a penicillin oral challenge test.4

¬ Nature of the reaction (diagnosis of the reaction) ¬ Active ingredient(s) thought to have caused the adverse reaction ¬ Assessment of likelihood (certainty it was caused by the active ingredient) ¬ Severity of event (consequences to the patient, for example hospitalisation) ¬ Date and location of the care (the original record may have more detail).

Note: in some cases the adverse reaction may be due to the formulation, batch, a combination of ingredients or the inactive ingredients.

Effect of Allergy Labels Antibiotic allergy labelling is common and negatively influences patient outcomes and antibiotic appropriateness.2 The presence of a penicillin allergy label has been associated with patients receiving less optimal and more broad spectrum antibiotics than necessary, the development of antibiotic resistance and increased risk of Clostridiodies difficile (C. diff), methicillin resistant staphylococcus aureus (MRSA), vancomycin resistant enterococci (VRE) infections and colonisation.² Penicillin allergies are reported by approximately 10% of the population.² However, evidence shows up to 90% of

penicillin allergy labels can be safely removed. 2,3 A significant number of allergies are likely to be inaccurate, with side effects such as nausea, vomiting or injection site reactions being reported as allergies.2 Also, penicillin allergies reported during childhood may no longer be an allergy after time, as approximately 50% of allergies are lost after five years.2 Obtaining comprehensive documentation of a patient’s adverse reaction to differentiate immunological from non-immunological reactions and determining the risk of antibiotic cross-reactivity can support accurate patient penicillin allergy labelling, guide treatment selection and

Chua et al4 implemented a whole of hospital program (in Melbourne) to assess the efficacy of inpatient delabeling of low risk penicillin allergies in hospitalised patients.4 In patients that were delabeled, there was an increase in narrow spectrum antibiotic use, improved antimicrobial prescribing, and a reduction in restricted antibiotic use.4 The authors concluded that the service successfully led to significant changes in preferred antimicrobial prescribing.4 Low-risk penicillin allergy delabeling is a strategy that health services could consider to support their AMS programs and improve use of antimicrobials to enhance patient outcomes.4 References are available on request.

Skin and Soft Tissue Infections Brigitte Janse van Rensburg, Icon Group Pharmacy Services Skin and soft tissue infections (SSTIs) are caused by microbial invasion of the skin and supporting structures, and management is dependent on by the location of the infection, severity and likely causative pathogens.1 This article reviews various common SSTI’s and guidelines for management.

Impetigo A bacterial infection which commonly affects the epidermis in children. 1,2 It can present in two forms: bullous and non-bullous. 1,2 Bullous impetigo is commonly caused by Streptococcus pyogenes (S. pyogenes) and appears as a honey-crust; whereas, non-bullous impetigo is caused by Staphylococcus aureus (S. aureus) and presents as a varnish-like crust. 1,2 Impetigo treatment depends on severity, with localised infections being treated with topical mupirocin 2% for 5 days, and

extensive disease requiring systemic antibiotic treatment with dicloxacillin or cefalexin for up to 7 days.2

Folliculitis Infection of hair follicles which generally occurs after exfoliation (S. aureus) or after hot tub/spa exposure (Pseudomonas aeruginosa). 1,3 Folliculitis tends to be self-limiting, and does not require antibiotic treatment; however, for severe cases bacterial swabs are recommended for cultures and susceptibility testing.3 If S. aureus is isolated, treatment with topical mupirocin 2% is recommended for five days.3

Cellulitis Infection of the dermis and subcutaneous fat layer. 1,4 Usually presents with spreading redness, warmth and swelling. 1,4

It may be accompanied by fever, lymphadenopathy in regional lymph nodes, and in some cases lymphangitis.4 Organisms typically implicated include S. pyogenes, S. aureus, Aeromonas spp. after fresh water exposure and Vibrio spp. after salt water exposure. 1,4 Treatment depends on the severity of infection and suspected causative organism. 1,4 S. pyogenes tends to be associated with nonpurulent, recurrent, or rapidly spreading, spontaneous cellulitis, whereas S. aureus more commonly causes purulent cellulitis associated with an abscess, penetrating trauma or has an associated ulcer.4 Treatment of cellulitis (as per Australian guidelines) is outlined in Table 1.4 Note, for cellulitis associated with hypotension or features of septic shock, it should be treated as a necrotising SSTI.4 Continued on page 4

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Table 1: Treatment of cellulitis (adults)4

Suspected organism

Treatment

Duration

Streptococcus pyogenes

Phenoxymethylpenicillin 500mg orally, 6-hourly

5 days

Staphylococcus aureus

Di/Flucloxacillin 500mg orally, 6-hourly

5 days

MRSA (OR S. aureus with immediate (nonsevere or severe) or delayed severe penicillin hypersensitivity)

Trimethoprim + sulfamethoxazole 160+800mg orally, 12-hourly OR Clindamycin 450 mg orally, 8-hourly

5 days

Mild cellulitis – without systemic features

Severe cellulitis/cellulitis - with systemic features Streptococcus pyogenes

Benzylpenicillin 1.2g intravenously, 6-hourly

Staphylococcus aureus

Flucloxacillin 2g intravenously, 6-hourly

MRSA

Vancomycin intravenously or depending on regional MRSA susceptibility patterns: Clindamycin or lincomycin 600 mg intravenously, 8-hourly

Intravenous antibiotics should be switched to oral when systemic features improve and continued for a total duration of 5 to 10 days

Notes: For patients with penicillin allergies, see Therapeutic Guidelines.

For patients treated with intravenous antibiotics, erythema can worsen for the first 48 hours after initiation of IV antibiotics.

Necrotising skin & soft tissue infections Necrotising infections include necrotising fasciitis and gas gangrene, have high mortality rates and need to be recognised and treated quickly, preferably with expert advice. 1,5 Necrotising SSTIs should be considered as a differential diagnosis in patients who are critically ill and present with a SSTI. 1,5 Clinical features of necrotising infections to look out for include: rapidly progressive infection, multiple systemic signs of toxicity, crepitus/ subcutaneous gas and disproportionate pain5. The cause of necrotising SSTIs can be monomicrobial (including S. pyogenes and Clostridium perfringes which causes gas gangrene) or polymicrobial.5 Treatment usually includes debridement and empiric antibiotics with a three-drug regimen, as explained in Table 2. 5

Table 2: Empirical treatment for necrotising skin and soft tissue infection (adults) 5

Empirical intravenous antibiotics Meropenem 1g, 8-hourly OR Piperacillin + tazobactam 4+0.5g, 6-hourly PLUS Vancomycin 25-30mg/kg loading dose, then dose adjusted as per guidelines PLUS Clindamycin 600mg, 8-hourly If wound has been immersed in water, Ciprofloxacin is included in this regimen (to provide cover for Aeromonas spp producing carbapenemase enzymes).

Ciprofloxacin 400mg, 8-hourly

Antibiotic treatment principles SSTIs are responsible for a large number of hospital admissions, with patients often staying on intravenous antibiotics for long lengths of time, which increases patient morbidity and can be associated with further risk for health-care associated infections.6 There is evidence that both early switch to oral therapy, and early discharge and switch to

outpatient antibiotic treatment, can be beneficial in the treatment of SSTI for decreasing length of stay in hospital, and patient morbidity. 1,6 Treatment should also be changed from empirical to more narrow-spectrum antibiotics at the earliest time possible once microbiology results are received from the pathology lab.1 References are available on request.

If you have any queries regarding Circuit content and authors please contact the Epic Pharmacy Practice Unit by email: circuit.editor@epicpharmacy.com.au Every effort has been made to ensure this newsletter is free from error or omission.

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