ANTIBIOTIC STEWARDSHIP

What is antibiotic stewardship?

Antibiotic stewardship is a systematic and consistent approach to promoting the correct and prudent use of antibiotics. It not only promotes the correct and effective use of antibiotics but also advocates against the unnecessary use of antibiotics. Although specifically geared to prescribers, i.e. medical doctors, there is also an important role for the public in terms of lowering their expectations for antibiotics when they are not necessary.

What are the main features of appropriate antibiotic therapy?

This includes the following:

Use of antibiotics only where necessary or where there is likely to be a bacterial infection

Antibiotic use directed towards the most likely pathogen, i.e. the prescriber bears in mind

the most likely cause of the infection and therapy subsequently adjusted, if necessary,

based on microbiological culture results

Antibiotic use guided by recent microbiological reports from specimens taken from the

patient

History of allergy and potential side effects of antibiotic prescribed is taken into

consideration

The therapy is given by the appropriate route, intravenously if acutely ill, orally if not so

acutely ill, and the dose is correct

The antibiotics are accompanied by other approaches such as surgical drainage in the

case of an abscess and removal of an intravenous line in case of catheter-associated

bloodstream infection.

Give examples of inappropriate therapy?

This includes:

The use of an antibiotic when not indicated, i.e. to treat a viral infection

The use of a particular antibiotic to which it can be anticipated that the pathogen is

resistant, e.g. a metronidazole to treat aerobic Gram negative bacillary infection

The wrong choice of antibiotic or the administration of the antibiotic by the wrong route

The use of multiple agents which have similar spectrums of activity. For example the use

of co-amoxiclav and metronidazole to treat a possible anaerobic infection

What are the potential consequences of inappropriate antibiotic use?

These include:

Increased mortality

Increased morbidity

Prolonged hospital stay

Increased financial costs due to ineffective treatment

Emergence and spread of antimicrobial resistance

Potential side effects for the patient, e.g. Clostridum difficile associated colitis

Why are antibiotics often used inappropriately?

There are a number of reasons for this, including a lack of education on the appropriate use of

antibiotics or the failure to have laboratory back-up. Therefore the main reasons are -

1. Lack of knowledge about the spectrum of the antibiotic

2. Lack of access to diagnostic facilities

3. Diagnostic uncertainty, i.e. 'treat just in case'

4. Time pressure, i.e. it is easier to write a prescription for a patient than to explain that the

viral infection is self-limiting.

5. Pressure from the pharmaceutical companies to use a new antibiotic

6. Habit

7. Patient expectations, i.e. the patient has come to the general practitioner and he or she

expects an antibiotic in return

How important is antibiotic use in the agricultural and veterinary sector?

Antibiotics are often used for the treatment of animals that have a bacterial infection. However, antibiotics are also used as growth promoters and to treat sub-clinical infection, in the hope of enhancing weight gain. This results in increased agricultural productivity. However, the use of antibiotics in the agri-food sector may result in the emergence of resistance which can be transferred to human pathogens; however this is a complex and controversial area. In recent years, the European Union and other international bodies have tried to restrict the use of antibiotics, especially those antibiotics that are also used in human medicine. For example, an

analogue of vancomycin has been banned as a growth promoter to help reduce the likely emergence and spread of vancomycin-resistant enterococci (VRE) to humans.

Give some examples of antibiotic resistant organisms in the community that have partly emerged

due to inappropriate antibiotic use?

Examples include -

Streptococcus pneumoniae increasing resistance to penicillin and to other antibiotics such as

the cephalosporins.

Beta haemolytic streptococci Group A, resistant to macrolides such as erythromycin and also

increasing resistance to tetracycline.

Mycobacterium tuberculosis, resistant in some countries to many agents resulting in multi-drug

resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB).

Eschericha coli, most strains of E. coli even in the community are ampicillin resistant.

Increasing levels of resistance to quinolone, cephalosporin and aminoglycoside antibiotics.

Give examples of antibiotic resistant bacteria that are a problem in hospitals?

These include -

MRSA

VRE

Extended-spectrum beta-lactamaseEnterobacteriaceae such as E. coli, Klebsiella

pneumonia, Serratia marcescens

Multi-drug resistant gram-negaitive bacilli; e.g Enterobacteriaceae, increasing

resistance to a wide range of antibiotics both nationally and internationally

Multi-antibiotic resistant Pseudomonas aeruginosa especially in the ICU

Acinetobacter baumannii, multi antibiotic resistant gram-negative bacillus (found

especially in the ICU)

What are the consequences of antibiotic resistance?

These include -

- Poor response to treatment as a result of the inappropriate prescription of a drug to which the

organism is resistant

- Sometimes increased mortality

- Cost. It is increasingly recognised that the financial costs of, for example infection with MRSA

are significant, for society, the healthcare sector and the individual patient.

Increased use of empiric broad spectrum antibiotics with associated side effects

e.g. Clostridum difficile associated colitis

How does Ireland compare internationally with other European countries in terms of our use of antibiotics?

Ireland is in about the middle of the "league table" in the consumption of antibiotics. As you can

see from figure 1, we use more antibiotics than countries such as the Netherlands, Estonia and

Austria, but not as much as in the southern European countries, e.g. France, Greece, Italy. In

general, there is a higher consumption of antibiotics during the winter here and elsewhere due to

respiratory tract infections.

What are the beliefs and attitudes of the public to antibiotics?

The correct answer is: Most members of the public have only a sketchy knowledge of the value and use of antibiotics. For example, many patients expect an antibiotic when they get a cold even though it is viral in origin and self limiting. Patients often don't understand the possibilities of resistance emerging, if not amongst bacteria that they carry, then in the general community. Unlike most other drugs, the prescription of an antibiotic has implications not only for the individual patient, e.g. adverse reaction, but also in the wider community as the emergence and spread of resistance affects us all.

What strategies and approaches can be used to minimise the emergence and spread of antibiotic resistance?

We can approach this from a number of perspectives:

We can prevent patients from getting infections in the first place, such as through the use

of vaccination in the community or through best practice in hospital, e.g. appropriate

hand hygiene.

We can also minimise the use or shorten the duration of use of invasive devices, e.g.

urinary catheters and intravascular lines which predispose a patient to infection.

We can diagnose infection effectively and promptly. This involves providing ready access

to diagnostic laboratories as well as radiology, and ensuring that the necessary expertise

is there to provide pre-analytical and post-analytical advice.

We can try to ensure that infections are treated wisely. Where an unusual or complicated

infection arises, advice should be sought from an appropriate expert, e.g. microbiologist

or infectious disease physician. Many hospitals now have an antibiotic pharmacist who

can also assist in ensuring patients are on appropriate antimicrobial treatment.

We can also use local or national surveillance data to ensure that empirical ("blind")

therapy is most likely to be effective, based upon data on antibiotic susceptibility from

laboratories

We can ensure prescribers have access to updated and accurate antibiotic guidelines for

the treatment of infections both in the community and in hospital

We can prevent transmission on infection through basic standards of hygiene, e.g. hand

hygiene, aseptic technique, good standards of personal hygiene, which will minimise the

occurrence of infection in both the hospital and in the community.