Michelle Wong

Lead Antimicrobial Pharmacist

Antibiotics

Aims and Objectives

How to access the Antimicrobial Formulary

What is expected for every antibiotic

prescription

MCQs

Audit

What are the signs of infection?

Systemic – Fever, rigors, delirium, chills, myalgia, headache,

anorexia, malaise

Peripheral/local – Erythema, pain, heat, swelling, pus

Vital signs – Temperature, tachycardia, hypotension,

tachypnoea

Is an antibiotic indicated?

Evidence of infection

– Clinical signs/symptoms

– Laboratory

Biochemistry

Haematology

Microbiology – previous results are very important

– Medical imaging

SAMPLE SAMPLE SAMPLE – allows for

targeted therapy

Empirical therapy

Grenade vs sniper approach

Broad vs narrow spectrum antibiotics

Broad spectrum

antibiotics

– Co-amoxiclav

– Quinolones

– Cephalosporins

– Tetracyclines

– Macrolides

– Piperacillin/tazobactam

– Meropenem

Narrow spectrum

antibiotics

– Trimethoprim

– Benzylpenicillin/

Phenoxymethylpenicillin

– Flucloxacillin

– Fusidic acid

– Vancomycin

– Gentamicin

General drug selection criteria

Age, weight (especially extremes), gender

Cautions/contraindications – Allergy (nature – to establish true allergy – cost of allergy, if

penicillin- explore previous cephalosporins/carbapenem

use), ADR, pregnancy/breastfeeding

Renal and hepatic function

Interactions – e.g antibiotics and warfarin,

oxycodone and clarithromycin

Route and bioavailability

Dose, frequency, duration

Glycopeptide

1st choice – vancomycin – local shortage

Used intravenously for MRSA infections,

alternative to penicillins for gram positive

cover

Requires renal function and therapeutic drug

monitoring

Max rate of administration 10mg/min

Oral - not absorbed

Teicoplanin higher dose used

Aminoglycoside

Gentamicin, tobramycin, amikacin

Nephrotoxic and ototoxic

Mainly use once daily except for infections such as endocarditis

Requires renal function and therapeutic drug monitoring

Rarely used for longer than 5-7days except for endocarditis

Extremes of weight – contact pharmacy

Calculator coming soon

What antibiotic information is available?

Antimicrobial Formulary for adults (plus summary) and

paediatrics available on the Intranet

AM app

http://www.bfwh.nhs.uk/mobile/amformulary/index.shtml

Vancomycin and gentamicin dosing guidelines

Surgical prophylaxis guidelines

Contact consultant microbiologists for antibiotic advice

Ward pharmacists

BNF

Antibiotic Prescribing Tips

Allergy box completed

Antibiotic, route, dose and frequency

Review date at 48 hours – sign and GMC number

Stop date (5 days if empiric)

Use the shortest duration of treatment suitable for the infection

Indication recorded on prescription chart, as well as medical notes

IV antimicrobials review after 48 hours – to oral?

Printed Name and bleep number

Antibiotic Prescribing Tips

Change from IV to oral guide CHORAL

Microbiological specimens

Time is essential

Management of MRSA/CPE – contact

microbiology

Dosing in Renal Impairment

Vancomycin/gentamicin guideline

Antimicrobial prophylaxis post-splenectomy

Start smart then focus

Prescribing Tips

48hours review and document outcome

– Stop

– Continue

– Switch

– IV to Oral

– OPAT

Prescribing Tips

RAG antibiotics list

Don’t forget incision and drainage/surgical

intervention may be the only option

Is this OK?

Good example

?Appropriate choice for UTI

Amoxicillin Resistance – January 2013 to December 2016

(% formulated using Resistant and Sensitive results on gram negative

organisms.)

Trimethoprim Resistance – January 2013 to December 2016

(% formulated using Resistant and Sensitive results on gram negative

organisms.)

Nitrofurantoin Resistance – January 2013 to December 2016

(% formulated using Resistant and Sensitive results on gram negative

organisms.)

Sample sensitivity review

MUST review relevant previous/current

sample sensitivity

High risk antibiotics for C difficile

Co-amoxiclav

Cephalosporins (especially 2nd/3rd

generations)

Ciprofloxacin (quinolones)

?Clindamycin (high dose used at BTH as

protective effect to CDT) Not same as

clarithromycin

GDH + & C. Difficile + Patients

GDH – Glutamate Dehydrogenase

GDH –ve

GDH +ve + C. Diff toxin –ve

GDH +ve and C. Diff toxin +ve

Therapeutic Drug Monitoring

Vancomycin Monitoring

Gentamicin monitoring

80 year old male, 80kg

(not obese)

Urosepsis

Creatinine

112micromole/L (CrCl

53ml/min)

Gentamicin level at

9:00am 2/1/12 =

3.1mg/l

What do you do?

Gentamicin monitoring

Taken too early - insignificant

Should be taken 1-4 hours before the 2nd

dose

Repeat level at ~6-9pm

Nursing to document time of administration

and time of sample in the medical notes

Key top interactions…

Antifungals/quinolones/rifamycins – LOTS of

interactions!

Most antimicrobials – Warfarin

Macrolides/Daptomycin/Fusidic Acid –

Statins

Daptomycin – Measure CK

Trimethoprim – Methotrexate

Aminoglycosides – IV diuretics

Clarithromycin and oxycodone/fentanyl patch

Clarithromycin is strong CYP3A4 inhibitors

INHIBITOR interaction is SIGNIFICANT

May increase the concentration of

oxycodone/fentanyl

Major incidents in real patients at BTH with

respiratory depression needing reversal with

naloxone

Question 1

Which ONE of the following is the most likely pathogen in Community acquired pneumonia?

a) Streptococcus pneumoniae

b) Pseudomonas aeruginosa

c) Moraxella catarrhalis

d) E.coli

e) Streptococcus pyogenes

Question 2

Which ONE of the following is the most

likely pathogen in exacerbation of COPD?

a) Streptococcus pneumoniae

b) Staphylococcus aureus

c) Haemophilus influenzae

d) Anaerobes

Question 3a

A 78 year old lady is admitted to hospital

with SOB, and coughing up green sputum.

CXR showed right basal consolidation.

Ur: 8.8, BP: 80/40, AMT: 10, RR: 23.

What is the severity of this patient’s pneumonia?

a) Mild

b) Moderate

c) Severe

Question 3b

For the same patient, what antimicrobial

treatment would you commence them on?

(Patient has no known drug allergies)

a) IV Co-amoxiclav + IV Clarithromycin

b) Oral Amoxicillin alone

c) Oral Amoxicillin + Oral Clarithromycin

Question 3c

For the same patient, which of the following

Microbiological specimens should you take?

a. Pneumococcal urinary antigen

b. Legionella urinary antigen – after speaking

to microbiologist or CURB 3 and above

c. Blood culture

d. Sputum sample

e. All of the above

Question 3d

The first results that come back for the patient are Pneumococcal Ag +ve, Legionella Ag-ve, what changes could you make to the patient’s treatment, if any?

a) Continue with same regimen

b) Stop IV Clarithromycin

c) Stop IV Co-amoxiclav

d) IV to oral switch for both Co-amoxiclav and Clarithromycin

Question 4

A patient is admitted with non-severe cellulitis and has a MRSA screen, the screen is positive. What antibiotic treatment would be appropriate?

a) Doxycycline

b) Flucloxacillin

c) Clarithromycin

d) Cefalexin

e) Speak to microbiologist

Question 5

Which of the following antibiotics are high-

risk for precipitating C. difficile infection?

a) Co-amoxiclav

b) Ciprofloxacin

c) Ceftriaxone

d) All of the above

Question 6

Which ONE of the following is a risk factor

for Clostridium difficile infection?

a) Morphine sulphate

b) Loperamide

c) Omeprazole

d) Paracetamol

e) Dalteparin

Question 7

A patient is receiving IV Vancomycin 1g OD for a

MRSA wound infection, your SHO asks you to switch

to oral treatment. Which of the following is the most

suitable action?

a) Sodium fusidate 500mg po tds

b) Rifampicin 600mg po bd + Doxycycline 100mg po bd

c) Vancomycin 250mg po qds

d) Flucloxacillin 500mg po qds

e) Contact microbiologist

Question 8

A patient is receiving Vancomycin 1g IV bd, a pre-dose level is taken before the 4th dose, the level is 25.0mg/L, what action would you take?

a) Continue with current regimen

b) Stop IV Vancomycin

c) Reduce dose to 1g OD

d) Increase dose to 1.5g BD

Question 9

Your SHO asks you to prescribe gentamicin for a

50year male patient with suspected urosepsis?

Seen on A+E. What information do you need?

1. Weight

2. Renal function

3. Previous A+E documention

4. All of above

Question 10

Your patient has been diagnosed with severe

Hospital Acquired Pneumonia. Has been started on

co-amoxiclav IV 1.2g TDS. History of CDT. What

do you do?

a) Speak to microbiologist regarding management

b) Add in metronidazole

c) Continue with co-amoxiclav

d) All of above

Audit

Data on compliance with the antibiotic

formulary done quarterly.

If interested in participating in an audit

contact antimicrobial

pharmacist/microbiologist

Any questions???

Good luck