+

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

+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”

+Introduction

Restrictions for other antibiotics: Broad spectrum cephalosporins Carbapenems Glycopeptides Flouroquinolones Others

Lack of specific guidelines or restrictions for piperacillin/ tazobactam

+Purpose

Review the indications and appropriateness of piperacillin/ tazobactam

Attempt to highlight hospital specific factors influencing prescribing

+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

+Methods

CategoryC- 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

+ResultsOverall

Category Number of Patients (n=78)

C- Concordant with guidelines 25 (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%)

+ResultsCategory C – Concordant with guidelines

Indication Number (n=25)Peritonitis 9

Diabetic Ulcer 4

Contaminated Wound 3

Animal/Human Bite 3

Aspiration Pneumonia 3

HAP – high risk 1

Febrile Neutropaenia 1

Necrotising Pancreatitis 1

+ResultsCategory NC(A) – Not concordant with guidelines but deemed an appropriate choice by ID Physicians

Indication Number (n=19)Abdominal infections 12

Skin infections 3

Respiratory infections 2

Urinary tract infections 2

Abdominal infections included:•appendicitis•cholecystitis•abscess•fistulae•bowel necrosis •non-specific infective surgical abdomen

+ResultsCategory NC(IA) – Not concordant with guidelines – inappropriate choice

Indication Number

(n=34)Poor antibiotic reasoning (47%)

No indication for antibiotic 11“Febrile Neutropaenia” (not meeting criteria for neutropaenia)

3

Prolonged post-surgical prophylaxis

2

Unnecessary broad spectrum of action (53%)

CAP 6Empirical UTI 4Cellulitis 2Wound infection – without systemic symptoms

2

+Breakdown by department

Chi- squared test P= 0.0049 Statistically significant difference between medical and

surgical teams

Appropriate Not Appropriate

Medical 12 20

Surgical 32 14

+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

+Limitations

Cross sectional, retrospective study

Sample size

Poor documentation

Did not formally analyse duration of therapy

+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

+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

+Questions?