Antibiotics: Introduction

Last updated: Sunday, June 13, 2021

NB: See learning outcomes for this tutorial mapped to competencies and a PDF of the whole text, and a one-page summary.

☞ Why this subject matters...

Antibiotic resistance is a serious, global problem. Every decision you make about antibiotics matters not just for your patient but for everyone. You therefore need to be able to guide antibiotic prescribing with confidence, considering the patient, the causative organism and the site of infection.

It’s a huge topic and this section cannot cover everything you will ever need to know, but it will give you a framework for reviewing an antibiotic prescription guide you how to tailor therapy to your individual patient and signpost you to current guidelines on commonly encountered infections.

Prescribing responsibly

Resistance occurs naturally over time, but inappropriate antibiotic use means that this problem has increased significantly over the last 40 years. That, together with fewer new antibiotics being developed, means quite simply that we may struggle to treat patients effectively in the future. It’s a worldwide issue but you have the potential to make a difference with every antibiotic prescription you review.

Public Health England have produced a strategy to tackle antimicrobial resistance and they recommend a “Start Smart – Then Focus” approach for every antibiotic prescription.

© Crown copyright 2017

Start Smart means 
 • Do not start antimicrobial therapy unless there is clear evidence of infection
 • Take a thorough drug allergy history
 • Initiate prompt effective antibiotic treatment within one hour of diagnosis (or as soon as possible) in patients with severe sepsis or life-threatening infections. Avoid inappropriate use of broad-spectrum antibiotics
 • Comply with local antimicrobial prescribing guidance
 • Document clinical indication (and disease severity if appropriate), drug name, dose and route on drug chart and in clinical notes
• Include review/stop date or duration
• Obtain cultures prior to commencing therapy where possible (but do not delay therapy)
• Prescribe single dose antibiotics for surgical prophylaxis where antibiotics have been shown to be effective
• Document the exact indication on the drug chart (rather than stating long-term prophylaxis) for clinical prophylaxis  

Then Focus means
• Reviewing the clinical diagnosis and the continuing need for antibiotics at 48-72 hours and documenting a clear plan of action - the ‘antimicrobial prescribing decision’.
• The five ‘antimicrobial prescribing decision’ options are:

1. Stop antibiotics if there is no evidence of infection
2. Switch antibiotics from intravenous to oral
3. Change antibiotics – ideally to a narrower spectrum – or broader if required
4. Continue and document next review date or stop date
5. Outpatient Parenteral Antibiotic Therapy (OPAT)

• It is essential that the review and subsequent decision is clearly documented in the clinical notes and on the drug chart where possible e.g. stop antibiotic.

Before choosing an antibiotic several factors need to be considered - the patient, the causative organism and the site of infection. The next few pages will guide you through the key considerations in making this decision.