1. + A Vitamin T Overdose? : An audit of piperacillin/ tazobactam use at Royal Perth Hospital Amelia Davis and Matthew Hanson Contributors: Dr Susan Benson, Dr Owen Robinson, Matthew Rawlins

2. + Background Piperacillin/ tazobactam (commonly: Tazocin) 4g + 0.5g tds B lactam + B lactamase inhibitor Broad spectrum: gram positive, gram negative* and anaerobes* Largely replaced ticarcillin/clavulanate (Timentin) in 2010 “Unrestricted”

3. + Introduction Restrictions for other antibiotics: Broad spectrum cephalosporins Carbapenems Glycopeptides Flouroquinolones Others Lack of specific guidelines or restrictions for piperacillin/ tazobactam

4. + Purpose Review the indications and appropriateness of piperacillin/ tazobactam Attempt to highlight hospital specific factors influencing prescribing

5. + Methods A cross sectional, point prevalence study National Antimicrobial Prescribing Survey 571 inpatients at Royal Perth Hospital on 14/11/12 To quantify and analyse the use of antimicrobials Identified patients on piperacillin/ tazobactam (n=78) Recalled patient notes Recorded indication for antibiotic, diagnosis, frequency of administration and prescribing department All non-concordant prescriptions reviewed by two ID Physicians

6. + Methods Category C- Concordant with guidelines NC(A)- Non- concordant with guidelines but deemed Appropriate by ID review NC (IA) – Non- concordant with guidelines (Inappropriate choice) F- Correct Choice but incorrect frequency Where C= Concordant with therapeutic guidelines or RPH guidelines

7. + Results Overall CategoryNumber of Patients (n=78) C- Concordant with guidelines25 (32%) NC(A)- Non- concordant with guidelines but deemed Appropriate by ID review 19 (24%) NC (IA) – Non- concordant with guidelines (Inappropriate choice) 34 (44%) F- Correct Choice but incorrect frequency 4 (5%)

8. + Results Category C – Concordant with guidelines IndicationNumber (n=25) Peritonitis9 Diabetic Ulcer4 Contaminated Wound3 Animal/Human Bite3 Aspiration Pneumonia3 HAP – high risk1 Febrile Neutropaenia1 Necrotising Pancreatitis1

9. + Results Category NC(A) – Not concordant with guidelines but deemed an appropriate choice by ID Physicians IndicationNumber (n=19) Abdominal infections12 Skin infections3 Respiratory infections2 Urinary tract infections2 Abdominal infections included: appendicitis cholecystitis abscess fistulae bowel necrosis non-specific infective surgical abdomen

10. + Results Category NC(IA) – Not concordant with guidelines – inappropriate choice IndicationNumber (n=34) Poor antibiotic reasoning (47%) No indication for antibiotic11 “Febrile Neutropaenia” (not meeting criteria for neutropaenia) 3 Prolonged post-surgical prophylaxis 2 Unnecessary broad spectrum of action (53%) CAP6 Empirical UTI4 Cellulitis2 Wound infection – without systemic symptoms 2

11. + Breakdown by department Chi- squared test P= 0.0049 Statistically significant difference between medical and surgical teams AppropriateNot Appropriate Medical1220 Surgical3214

12. + Frequency/Dose Frequency 3 incidences of bi- daily dosing 1 incidence of alternate day dosing All documented to be due to “renal impairment” None actually met criteria for reduced dosing (GFR <20ml/min) Dosing All 78 prescriptions 4 + 0.5g

13. + Limitations Cross sectional, retrospective study Sample size Poor documentation Did not formally analyse duration of therapy

14. + Conclusions What we do well Piperacillin/ tazobactam was appropriate in 56% Common appropriate indications: Peritonitis Diabetic ulcers What we don’t do so well Piperacillin/ tazobactam was inappropriate in 44% Poor antibiotic reasoning Unnecessary use of broad spectrum Documentation

15. + Further Questions Raised? Why are we prescribing inappropriately? Over treating? Medical vs Surgical? Restricted use of other antibiotics? Concern about risk of toxicity with aminoglycosides use? What do we do now? Education re: common inappropriate uses Improve documentation

16. + Questions?