ANTIMICROBIAL STEWARDSHIP PROGRAM
ANTIMICROBIAL STEWARDSHIP
FIVE QUESTIONS TO ASK BEFORE PRESCRIBING
J SCOTT WEESE DVM DVSC DIPACVIM ONTARIO VETERINARY COLLEGE UNIVERSITY OF GUELPH
Antimicrobial stewardship is a coordinated approach to optimizing the use of antimicrobials and maximizing patient care , while minimizing the risk of resistance , toxicity or other adverse events . A well-structured and functioning antimicrobial stewardship program can improve patient care and facilitate effective treatment . The Fall 2019 issue of College Connection includes information about antimicrobial stewardship in veterinary medicine .
What am I treating ?
A definitive diagnosis is not usually available at the time treatment is started , but history , clinical signs and patient side / in-clinic testing can usually provide a good presumptive diagnosis . Empirical antimicrobial use is absolutely justifiable if there is reasonable suspicion of a bacterial infection that cannot be addressed through other approaches .
However , antimicrobials are also often used in situations where bacterial infection is unlikely or , if present , is likely self-limiting ( e . g . kennel cough ). Critical thought should go into the likely disease process and whether there is truly a need for antimicrobials . There is often pressure , either from the client or from ourselves , to “ do something ”. Sometimes , doing nothing is the best approach .
What bacterium is involved ?
While culture and susceptibility testing results are ideal , testing is not always possible and decisions must usually be made before results are available . Regardless , the adage ‘ common things occur commonly ’ applies to most bacterial infections . Some diseases have predictable causes ( e . g . pyoderma is usually caused by staphylococci ). Some bacteria have predictable susceptibility patterns ( e . g . streptococci are typically susceptible to penicillins ). Clinician experience regarding treatments that typically work in similar patients ( e . g . most dogs with bacterial cystitis respond to amoxicillin ) and understanding of local susceptibility patterns from similar cases where cultures were performed can help guide initial therapy or cases where cultures cannot be performed .
Is there anything else I should do ?
Antimicrobials are sometimes the sole solution to a problem . However , the disease process is often more complex and antimicrobials may not be enough to provide short term clinical cure or longterm success . Many infections are secondary to an underlying disease or risk factor . Failure to identify and address those can reduce the likelihood of successful treatment and increase the chance of recurrent infection . For example , superficial bacterial folliculitis in dogs is secondary to skin barrier damage , often from allergic skin disease . Treatment of secondary staphylococcal disease may result in short term clinical cure , but if allergic skin disease is not addressed , it is almost certain that infection will recur . Therefore , in the overall picture , the course of antimicrobials did not truly help the patient , it just moved the current infection to a later date , resulting in more antimicrobial use , more patient morbidity , more owner cost and frustration and a greater chance that the next infection will be caused by a resistant bacterium .
What ‘ tier ’ is my chosen antimicrobial ?
Essentially all antimicrobials used therapeutically in animals are classified as ‘ medically important ’ in human medicine . However , the degree of importance varies and antimicrobials can be further classified based on their importance for treatment of infections in people and whether there is evidence linking use in animals to resistance in bacteria that cause disease in people . There are minor differences between Canadian and World Health Organization lists , but the general classifications are fairly similar . Particular scrutiny is paid to the use of 3rd generation cephalosporins and fluoroquinolones . Both drug classes have products licensed for use in Canada and there are many situations where they are appropriate to use . However , less important drugs can often be substituted .
What ’ s my de-escalation plan ?
Sometimes , it is necessary to use broad spectrum antimicrobials at the onset of treatment , because of the unclear nature of the infection or likely antimicrobial susceptibility . Empirical broad spectrum therapy is entirely appropriate in many situations . However , that does not mean that broad spectrum coverage is required throughout the treatment period . De-escalation to a narrower spectrum ( e . g . stopping one drug when two drugs are used initially ; changing a single broad spectrum antimicrobial to a narrower spectrum drug ) can often be performed once laboratory tests are available and based on patient response . Anytime broad spectrum antimicrobials or antimicrobial combinations are used , there should be a plan to re-assess the need and to de-escalate when possible .
2 College Connection Fall 2020 cvo . org