On June 3rd, the AVA released a statement welcoming the new “National Strategy for Antimicrobial Resistance” that the federal government had released the previous day. After reading the Strategy, it got me thinking about how we use antibiotics and what we could be doing better.
Why has antimicrobial resistance happened?
There are many factors involved here. Inappropriate choice of antibiotic, incorrect dosage or length of course, and client compliance are all implicated (in companion animal medicine at least). Of course, the problem is much larger than that, but here I will be concentrating on what WE need to consider.
Why is it so important?
Antimicrobial resistance is now recognised as a serious global health priority, threatening both veterinary and medical practice. If it continues, it could mean that we end up in a situation where simple infections cause serious illness and even death. Imagine a world without antibiotics…….it doesn’t bear thinking about does it?!
Why don’t the drug companies just make new antimicrobials?
This is a very common question, but it is not as easy as it sounds. In the last fifty years, there have only been two novel antibiotics developed for use in human medicine. This is because the cost of developing new drugs is phenomenal, and unfortunately there would be relatively low return because any new drug would be reserved for those cases where other antibiotics are ineffective rather than being released for general use.
Therefore the development of new antibiotics is NOT the answer.
What can we do?
We (veterinary, medical AND agriculture) need to protect the antibiotics that we currently have, by responsible usage. The medical profession is generally far ahead of us on this, but even there, there is room for improvement.
A few years ago, the BSAVA and SAMSoc (the Small Animal Medicine Society) came up with an initiative called ‘PROTECT’. I believe that this is an excellent framework for all veterinarians to work from.
Coming up with a practice policy for ‘empirical prescribing’ is invaluable. This ensures everyone is working in the same way, and using appropriate medications.
Antibiotics will not replace the need for surgical asepsis. They are only appropriate in a few specific cases (eg immunocompromised patients)
Reduce inappropriate useage (due to client pressure etc) – eg for viral diseases/self limiting diseases use symptomatic treatment such as anti-inflammatories and cough suppressants.
Use cytology and culture to ensure that appropriate antibiotics are always used.
Use topical preparations rather than systemic.
Types of bacteria and drugs:
Consider anaerobic vs aerobic, Gram +ve vs Gram –ve. Think about distribution and penetration of antibiotics (eg lincosamides such as clindamycin concentrate well in sites such as prostate and mammary tissue)
Employ narrow spectrum:
Narrow spectrum antibiotics reduce the selection pressure on commensal organisms (eg gut bacteria). Reduce useage of certain antibiotics (have First line, Second line, Third line etc).
Culture and sensitivity:
Use this promptly if long courses are going to be required (eg deep pyoderma) or if empirical dosing has failed.
Treat for an appropriate length of time, and at the correct dose. Ensure that you never underdose.
What do you think? Does your clinic have protocols in place? How closely do you consider the type of antibiotic you are using? The W.H.O has a list of antibiotics classed as ‘critical to human health’ and advises that fluoroquinolones and 3rd/4th generation cephalosporins (excluding cefovecin (Convenia)) should NOT be used as first line, but reserved for cases where there is a positive culture.
photo courtesy commons.wikimedia.org