BY DR PAUL BARTLEY
The cover photograph on old, book-versions of the Australian Therapeutic Guidelines-Antibiotic is of a blood agar plate featuring colonies of Penicillium chrysogenum and Staphylococcus aureus – a modern facsimile of Fleming’s original experiments demonstrating the antibacterial activity of penicillin. One of Fleming’s subsequent insights was that S. aureus was capable of restricted growth in low concentrations of Penicillin and effectively predicted the potential for these emerging compounds to induce antibiotic resistance and therefore risk treatment failure.
Collectively, antibiotics are typically drugs with a broad therapeutic index (with notable exceptions) which, when prescribed in an evidence-based manner, are profoundly effective in reducing morbidity and mortality consequent to infection. However, throughout the ‘golden’ antibiotic era, all classes of micro-organisms, but especially bacteria, have demonstrated their ability to acquire resistance mechanisms to compounds which they were previously susceptible.
Notable examples include penicillin and methicillin resistance in S. aureus, extended-spectrum betalactamase (ESBL) production by E. coli, penicillin-resistant Neisseria meningitidis, extended drug resistant strains of Neisseria gonorrhoeae, ceftriaxone and ciprofloxacin-resistant strains of Salmonella Typhi, multidrug and extended drug-resistant strains of Mycobacterium tuberculosis and quinine-resistant Plasmodium falciparum.
The successful treatment of these leaves the patient and treating clinician with options limited to third-line, costly or more toxic drugs that very often can only be administered in a hospital or hospital-in-the-home intravenous program; and frequently an increased mortality risk. Currently, 700,000 deaths per year (worldwide) are directly attributable to multi-resistant organism infections, representing a major, emerging public health problem. Deaths from multiresistant organism infections are predicted to reach 10 million per annum by 2050. Additionally, a lack of antimicrobials could significantly restrict future capacity for many procedures including organ transplantation, cancer chemotherapy, major surgery and treatment of diabetic complications.
Some decades ago, ‘dirty hospitals’ took much of the obloquy for the selection and transmission of ‘superbugs’ as a consequence of antibiotic misuse, overuse and poor infection control practices. In response, there have been dramatic, evidence-based improvements in infection control, antibiotic management, antimicrobial stewardship and hospital regulation and administration that have been instrumental in improving patient safety and reducing the risk of selecting and transmitting multiresistant organisms and the separation of the prescribing of medicines from dispensing.
However, many of the multi-resistant pathogens listed above have been selected as a consequence of treatment in the community, whether or not the patient was treated in a Western or developing country. Antimicrobial resistance occurs where antimicrobials are prescribed. It is essential that antimicrobial susceptibility be preserved for our patients for as long as possible.
Antimicrobial stewardship has been part of the normal practice for infectious disease physicians and medical microbiologists for decades. It has evolved into a true multi-disciplinary process that includes pharmacists, nurses, hospital administrators and doctors from other disciplines; and is a mandated accreditation requirement for all hospitals by the ACSQHC. Nationally, antimicrobial stewardship also includes the veterinary and agricultural sectors. Within hospitals it dovetails in with infection control, vaccination strategies and hand hygiene programs to reduce the risk of patients acquiring infections, in addition to minimising the selection and transmission of multiresistant pathogens.
The stewardship process emphasises the importance of collecting appropriate cultures before commencing antibiotics therapy - not only the ‘correct’ antibiotic, but also the revision of treatment when culture results are available, the role of surgical drainage and removal of redundant devices, the use of an antibiotic with an appropriate spectrum for the appropriate duration. Audits according to nationally standardised criteria.
Antimicrobial stewardship opportunities exist in all disciplines of medicine and is a process that all Doctors, to varying extents need to support and participate in, commensurate with their practice. Such examples include the appropriate timing of pre-operative antibiotic prophylaxis, using narrower-spectrum agents for non-severe lower-respiratory tract infection, avoiding antibiotic use for viral URTI, delayed prescribing strategies for patients with early or protean symptoms, and switching to narrower spectrum agents when cultures demonstrate susceptibility.
Many clinicians may find this daunting, and for some could represent significant practice changes – but this needs to be balanced with the knowledge of the potential harms of antibiotics, the harm from multi-resistant organism infection (including increased mortality risk for our patients) and the benefits accrued from using narrower spectrum agents. There are numerous CPD programs to support clinicians in this process.
The responsibility of prescribing is conferred to medical graduates after demonstrating sufficient aptitude in the diagnosis and management of the whole patient with any particular disease. Given the history of antimicrobials and the emerging threat of antimicrobial resistance, it is difficult to therefore understand the approach taken by the Queensland Minister for Health, the Honorable Stephen Miles MLA, to allow the prescriptions of trimethoprim by pharmacists – whose primary qualifications do not include training in the diagnosis or management of disease – directly to patients for the treatment of urogenital symptoms against the express advice to the contrary from Australian Medical Association Queensland, the Australasian Society for Infectious Diseases, the Australian College of Rural and Regional Medicine and the Royal Australasian College of General Practitioners. In addition to diminishing the impact of many Queensland Health initiatives to tackle antimicrobial resistance; and dismissive of Medical training and CPD requirements, the ersatz rationale for this decision risks harming our patients and the decision needs to be reversed.
Dr Paul Bartley, BMedSc, MBBS, FRACP, FRCPA, PhD, Infectious Diseases Specialist, Wesley Hospital, Brisbane; Co-Chair of the Uniting Care Health Antimicrobial Stewardship Committee; and AMA Queensland Infectious Diseases Specialist spokesman.
Published: 30 Aug 2019