Antibiotic prescribing : Why is it an issue? Ian Battersby BVSC DSAM DipECVIM FRCVS

Antibiotic History www.vetspecialists.co.uk

No new class of antibiotics since 1980s How have we been using a commonly prescribed drug? Unlike other drugs the more we use them their efficacy wanes…. www.vetspecialists.co.uk

Complex Issue Human Veterinary – Different species Mass prophylaxis Welfare Environment Different countries : legislation e.g. Scandinavia Different opinions ! Common thought – we recognise action is needed www.vetspecialists.co.uk

MDR Bacteria Who are the main players? Variety of Gram negative and Gram positive ‘ESKAPE’ pathogens Enterococcus faecium Staphylococcus aureus Klebsiella pneumonia Acinetobacter baumannii Pseudomonas aeruginosa Enterobacter species

How do Antibiotics influence Resistance Development…..

X

Bacterial Hyper-Mutational State The simpsons Antimicrobial level not high enough to inhibit/kill bacteria Mechanisms to repair DNA replication errors in bacteria are inhibited

Too often Too Long Poor Dosing Sub Therapeutic Levels

Practice Infection Control Policy Hygiene/barrier nursing protocols Hygiene/barrier nursing protocols Antibiotics Prescribing Policy (or stewardship) Monitoring Monitoring How effective can these policies be…

J Small Ani Pract. June 2011;52(6):310-8. Therapeutic antibiotic use patterns in dogs: observations from a veterinary teaching hospital. J Small Ani Pract. June 2011;52(6):310-8. OBJECTIVES: To describe therapeutic antibiotic use patterns in dogs at a small animal teaching hospital. METHODS: A retrospective case analysis of randomly sampled antibiotic prescriptions in dogs from May 20th 2008 to May 20th 2009 RESULTS: 17% of therapeutic antibiotic prescriptions there was confirmed infection, 45% suspected infection 38% there was no documented evidence of infection.

Changing our prescribing habits

Changing Habits is Hard The challenge “ prescribe antibiotics just in case” vs. “ prescribe as they are indicated” Changing Habits is Hard Forming habits from N = 1

Were Abi prescribed ?

Were Abi prescribed ? Puppy Not vaccinated Vomiting and Haemorrhagic diarrhoea Pyrexic Hypovolaemic, tachycardic

Were Abi prescribed ? Relatively Bright , Hydration Good 2 episodes of diarrhoea in 12 hours Likes to scavenge! Eating and drinking Examination NAD

Were Abi prescribed ? 24 hours Anorexic Lethargic Diarrhoea 3x hr Borborygmi Vomiting Is drinking

Were Abi prescribed ? 24 hours Anorexic Lethargic Diarrhoea 3x hr Borborygmi Vomiting Is drinking

Human Acute Diarrhoea Guidelines

Consider the specificity of your findings for bacterial infection…   Antimicrobials No Antimicrobials Fever Bacterial Infection viral, protozoal, Fungal Sterile inflammatory disease Immune mediated disease Para-neoplastic Metaphyseal osteopathy Stress Other example neutrophilia or protein in the urine

Is there a bacteria infection involved?? Cytology Culture Procalcitonin in humans - pneumonia and sepsis

“Antibiotics are not a substitute for poor asepsis” Surgical prophylaxis. “Antibiotics are not a substitute for poor asepsis”

In vitro resistance vs. Clinical ( in vivo) resistance

Clinical Resistance/Failure Bacteria factors Host factors Pharmaco dynamics of the drug WBC, cytokine, Ab, Comp In vitro sensitivity* Virulence factors Blood supply, necrosis, drainage Individual drug properties * MIC limitations Rex and Pfaller (2002) – The 90:60 rule

Clinical Resistance/Failure Bacteria factors Host factors Pharmaco dynamics of the drug WBC, cytokine, Ab, Comp In vitro sensitivity* Virulence factors Blood supply, necrosis, drainage Individual drug properties * MIC limitations Rex and Pfaller (2002) – The 90:60 rule

Siberian Husky – Anal abscess

ANTIBIOTIC PSEUDOMONAS E.COLI ENTEROCOCCUS Amoxycillin RESISTANT RESISTANT RESISTANT Amoxycillin-Clav RESISTANT RESISTANT RESISTANT Cephalexin RESISTANT RESISTANT RESISTANT TMS RESISTANT Sensitive RESISTANT Gentamicin Sensitive * Sensitive * Sensitive * Marbofloxacin Sensitive Sensitive RESISTANT Erythromycin RESISTANT RESISTANT RESISTANT Fusidic acid RESISTANT RESISTANT RESISTANT Clindamycin RESISTANT RESISTANT RESISTANT

Clinical Resistance/Failure Bacteria factors Host factors Pharmaco dynamics of the drug WBC, cytokine, Ab, Comp In vitro sensitivity* Virulence factors Blood supply, necrosis, drainage Individual drug properties * MIC limitations

We want to Treat Effectively but not too long How long…………………..?

Duration of Course Humans – Cochrane Reveiw Uncomplicated UTI – young women 3 days vs 5-10 day older women 3-6 d vs. 7-14 Pyelonephritis (non hospitalised) 7-14d vs 14-42 d

Spectrum of Activity – Practice policy Hard to do…. MTZ , aminoglycosides Avoid combinations therapy Avoid using certain antibiotics as first line agents There are very strong arguments that antibacterials with restricted use in human medicine (e.g. imipenem, linezolid, teicoplanin, vancomycin) should not beused in animals

Thank you for listening 