Using the Guide

On behalf of the Microbiologists, we would like to thank Rebecca Bond and Dr Jim Gardner for their help and support in the development and implementation of this policy.

On call microbiologist – Ext 3542/bleep 774

Dr R Palmer
Consultant Microbiologist
Nerve centre or ext: 53754 or contact via switchboard

Michelle Wong
Antimicrobial Pharmacist
Ext: 52196, Bleep: 448

Pharmacy Medicines Information Department
Ext: 53791

Microbiology Department
Ext: 56951 (Bacteriology Laboratory)
Ext: 56952 (Virology Laboratory)

Biochemistry Department
Ext: 24757

Infection Prevention and Control Department
Ext: (53874 / 22051 / 22120)

  • Updated advice around the management of Clostridium difficile as per latest NICE guideline.

  • Prompt and appropriate treatment of patients with sepsis should not be delayed on account of an undue anxiety regarding C. difficile infection.
  • Co-amoxiclav, Quinolones, 2nd/ 3rd generation Cephalosporins are considered high risk drivers for C. difficile infections [CDI]. However, CDI may be associated with most other antibiotics.
  • Their use should be as per formulary after assessing patient’s risk for CDI and following discussion or on advice of Consultant Microbiologist or ID physician during working hours.
  • Co-amoxiclav and Ciprofloxacin will now be restricted to Consultant Microbiologist approval for non-formulary indications.
  • High dose Clindamycin: Higher dose (600mg q6h) of Clindamycin has been shown to offer protective effect against C. difficile infection
  • Risk factors for C. difficile infection: (High risk if 2 or more)
    • Elderly patients (>70 years of age)
    • Long length of stay in healthcare settings
    • Recent use of high risk antibiotics (Co-amoxiclav, Quinolones, 2nd/ 3rd generation Cephalosporins)
    • Recent major surgery (especially gastrointestinal surgery)
    • Serious underlying disease or illness
    • Immuno- compromising conditions
  • Previous C. difficile infection (GDH+/CDT+) or C. difficile carriage (GDH+/CDT-ve) is classified as high risk. Microbiologist input for antibiotic management is essential.
  • Meropenem resistant Pseudomonas and Enterobacteriaceae are a much more serious problem globally and are being encountered in the region including Blackpool Teaching Hospitals. This has resulted from unrestricted and overuse of carbapenems.  Meropenem use in this formulary is hence restricted to responsible primary Consultant or Consultant Microbiologist/ID Physician approval only.

The primary objective of this formulary is to ensure the appropriate selection of antimicrobials for the treatment of common infections.  The choices of antimicrobials included in the formulary have been carefully selected to move to equally efficacious agents with a lower risk of precipitating health care associated infections, including MRSA, Clostridium difficile and multidrug / pan drug resistant Enterobacteriaceae / Pseudomonas.

These guidelines are evidence based and the antibiotic choices reflect local health care associated problems, epidemiology and antibiograms. These guidelines specify the recommended antimicrobial, dose, route and duration of treatment for common infections encountered in General Medicine and Surgery.

The doses mentioned in this formulary are for adults with normal renal and hepatic function and of usual normal body build. Please speak to your ward pharmacist or contact Pharmacy Medicines Information for advice on dosing in renal or hepatic impairment or in patients with extremes of weight.

  • Prior to prescribing an antibiotic the prescriber MUST consult all available information on previous isolates to ensure there is no information on prior resistance which might preclude the choice of empiric organism and consider previous antimicrobial use. If this is the case please discuss with Microbiologist/ID Physician for advice on alternative agents during working hours.
  • Antimicrobials should only be prescribed where there are good clinical indications.
  • Every effort should be made to collect relevant specimens for microbiological investigations prior to starting antimicrobial therapy.
  • ALL antimicrobials should be reviewed DAILY as best practice. Empiric antimicrobial prescriptions should be reviewed daily ( or definitely at 48/72 hours and correlated with patient’s response and/or available diagnostics). Broad spectrum antimicrobial agents should be de-escalated to narrow spectrum agents and/or oral agents as per sensitivity results. All antimicrobials have an automatic stop date at 5 days so should be reviewed and re-prescribed as necessary.
  • Writing an antibiotic prescription:
    • The Choice of agent (as per formulary), dose, route, start date, indication/ working diagnosis, date of review/ stop, name and contact/ bleep information and GMC number of prescriber MUST be clearly printed.
    • Times of administration (e.g. 0600h, 1200h, 1800h, etc) instead of morning, midday, evening should be written.
    • Above information should be clearly documented in both the medical notes and on the prescription chart
    • Review date must be written
    • The stop date and anticipated course length should be clearly documented as per the formulary recommendation or otherwise specified by microbiologists
    • The above will be considered for audit standards.
  • Antimicrobial therapy should be prescribed according to the formulary which is informed by local pathogen epidemiology and local antimicrobial sensitivity patterns.
  • Narrow spectrum antimicrobials should be prescribed in preference to broad spectrum antimicrobials where possible in conjunction with microbiology results or discussion with a microbiologist.
  • Indications requiring longer treatment require re-writing of prescription [indicating the original start date of the antibiotic and planned duration].
  • Oral agents with excellent bioavailability can be used instead of intravenous agents – discussed with microbiologists.
  • Responsible consultant must consider risk of C. difficile infection in high-risk patients. Antimicrobials with a high risk of precipitating Clostridium difficile infection (e.g. Co-amoxiclav, Cephalosporins and Quinolones) should be avoided for safer alternatives or used with caution, where benefits outweigh risks.
  • Antimicrobials with a lower risk of subsequent Clostridium difficile infection (Clarithromycin, Doxycycline and Gentamicin) should be used instead.
  • Do NOT prescribe from restricted list antimicrobials without Consultant Microbiologist approval and document this in the medical notes.
  • Expert advice should be sought from a medical microbiologist for complicated infections, interpretation of culture and sensitivity results or in the case of failure of empiric treatment.
  • Choice of antimicrobials must be carefully considered when prescribing for patients with previously/ currently known carriage/ infections with MRSA, multi-drug resistant coliforms or C. difficile. Discuss with Microbiologist during work hours if patient specific advice required.
  • Offer advice about important side effects for antimicrobials as per BNF.

Patients commonly report adverse reactions to antibiotics, especially the Penicillin group.  It is therefore very important to clarify the nature of the adverse reaction.

Patients often report to being “allergic” to an antibiotic, when in fact they experienced a common adverse drug reaction (e.g. diarrhoea or vomiting) rather than an allergic reaction (e.g. rash, angioedema or anaphylaxis).  In these cases the benefits of using a Penicillin-based regimen probably outweigh the risks.

1) When assessing whether the person is presenting with a NEW possible drug allergy – take a history and undertake a clinical examination as per NICE guidance on drug allergy.

Document the following:

  • the generic and proprietary name of the drug or drugs suspected to have caused the reaction including the strength and formulation
  • the reaction,
  • a description of the reaction
  • the indication for the drug being taken (if there is no clinical diagnosis, describe the illness)
  • the date and time of the reaction
  • the number of doses taken or number of days on the drug before onset of the reaction
  • the route of administration
  • which drugs or drug classes to avoid in future.

2) For existing drug allergy status, record all of the following at a

  • the drug name
  • the signs, symptoms and severity of the reaction
  • the date when the reaction occurred.

For all patients reporting an adverse reaction to an antibiotic (or any drug), the above should be documented in the drug allergy box on the front of the prescription chart. Check with the patient, the patient’s GP or in old medical notes to find the nature/ severity of the allergy.

The type of hypersensitivity reaction with Penicillin or other antimicrobials (eg. rash, anaphylaxis, etc) MUST be obtained (when possible) and clearly documented in case notes and drug chart.

Patients with a true allergy to penicillins should be considered allergic to other Penicillin’s (e.g. Augmentin® (Co-amoxiclav), Tazocin® (Piperacillin-tazobactam) and Amoxicillin).

The risk of crossover allergy is reported as 10% for Cephalosporins, though review of published evidence suggests a much lower chance of crossover allergy. Crossover has also been reported with Carbapenems (e.g. Meropenem, Ertapenem and Imipenem), approximately 8-11%.

Use of any Cephalosporins or Carbapenems without adverse event in a Penicillin allergic patient should be clearly noted in case notes and drug chart. This can be achieved by review of notes or discussion with the GP.  If the patient has a non-serious allergy to Penicillins (e.g. mild rash), Cephalosporins/ Carbapenems could still be used with caution as an alternative to Penicillins and the patient should be closely monitored.

Individuals with a history of anaphylaxis, urticaria, or rash immediately after penicillin administration are at risk of immediate hypersensitivity to a penicillin; these individuals should not receive a penicillin. As patients with a history of immediate hypersensitivity to penicillins may also react to the cephalosporins and other beta-lactam antibiotics, they should not receive these antibiotics, if no documentation of receipt of Cephalosporins is available and the patient has an anaphylactic allergy to Penicillins; then Cephalosprins or Carbapenems should not be used.