Antimicrobial Stewardship

Prudent Antimicrobial Prescribing

This guidance is based on the best available evidence but its application must be modified by:

  • Professional judgement.
  • Recent microbiology results or antibiotic treatment
  • Known carrier status of patients e.g. MRSA, Clostridium difficile toxin and resistant organisms such as ESBL producing coliforms
  • Severity of illness
  • Immunosuppression
  • Age
  • Renal/hepatic function
  • Potential drug interactions (including oral contraceptive pill)
  • Drug allergies and nature of allergic reaction
  • Pregnancy, breastfeeding

Antimicrobial Prescribing Principles

  1. Prescribe an antibiotic only when there is likely to be a clear clinical benefit. It is imperative that in order to rationalize therapy, appropriate and timely samples are taken. The results must be actively followed up by medical staff.
  2. Start – stop / review dates for antimicrobials should be documented on HEPMA to prevent unnecessary prolonged treatment.
  3. The use of antibiotics such as Co-amoxiclav, Ciprofloxacin, Clindamycin and Cephalosporins (4C antibiotics) are associated with the acquisition of Clostridium difficile.
  4. Always determine the nature of any allergy and how genuine it is prior to prescribing antimicrobials.
  5. Avoid the use of Gentamicin for more than three days except in endocarditis or where otherwise clinically indicated. Close monitoring of Gentamicin levels and renal function is compulsory in all cases.
  6. Avoid use of topical antibiotics (especially those agents which are also available as systemic preparations) except for eyes/ears or MRSA eradication
  7. Where empirical therapy has failed seek senior clinical review and check existing microbiology results in the first instance.


Simvastatin (any dose) should not be taken concomitantly with clarithromycin or erythromycin. Patients on doses of atorvastatin > 20mg/day should not receive concurrent treatment with clarithromycin.

Doxycyline – should not be taken for 2 hours before or after indigestion remedies or medicines containing iron or zinc as the effectiveness can be significantly reduced.



  1. This Model has been adapted to take cognisance of relevant national guidelines and local sensitivity patterns.
  2. Doses are oral and for adults unless otherwise stated assuming normal renal and hepatic function
  3. Please refer to BNF and Summary of Product Characteristics for further information
  4. Dosing frequencies: OD= once a day,  BD = twice a day, TDS = three times a day, QDS = four times a day

Produced by The Antimicrobial Management Group, July 2017 Approved by Area Drug and Therapeutics Committee

Updated July 2020

Review date: July 2023