Antimicrobial Therapy General Notes

Resistance to antibiotics and other antimicrobials is recognised locally and nationally as a major threat to public health and patient safety.  The prevalence of antimicrobial resistant bacteria and other healthcare associated infections is partly governed by antimicrobial usage.  Prescribers are therefore encouraged to prescribe antibiotics prudently and follow local and national guidelines as a matter of good clinical governance.
Empirical recommendations for antimicrobial therapy are based on local epidemiology and resistance patterns and advise the non-specialist on the most appropriate antimicrobial for the initial treatment of common infections. It does not include other aspects of management. 

Principles of Treatment

  1. Prescribe an antibiotic only when there is likely to be a clear clinical benefit.
  2. It is important to use the correct dose and appropriate course length.
  3. Do not prescribe an antibiotic for viral infections. 
  4. Use simple generic antibiotics if possible.  Avoid broad spectrum antibiotics (e.g. co-amoxiclav, quinolones and cephalosporins) when narrow spectrum antibiotics remain effective, as they increase risk of Clostridium difficile, MRSA and resistant UTIs.
  5. Where a 'best guess' therapy has failed or special circumstances exist, microbiological advice can be obtained from the on call microbiologist via ARI switchboard (0845 456 6000).

Specialist Advice

For patients with a history of infection with meticillin-resistant staphylococcus aureus (MRSA) or extended spectrum beta-lactamases (ESBLs) specialist advice about choice of antibiotics should be sought from medical microbiology.

Further advice on treatment is available from the on-call Medical Microbiologist, Specialist Antimicrobial Pharmacist or Infection Unit Physician.
Suitable samples should be taken where appropriate and sent to microbiology with a clinical history.  On the receipt of culture results, the choice of antimicrobial should be reviewed, taking into consideration antimicrobial sensitivities, patient factors (refer to penicillin allergy policy), toxicity, and cost-effectiveness.
If there is no response to initial treatment or if the infection recurs, specialist advice should be sought.

Dosing and Duration

Recommended adult doses and durations of treatment have been included but often this will depend upon clinical judgement in the individual case.  Most infections will normally respond to a three to ten day course. Doses in the policy are for adults only unless otherwise stated, and assume normal renal and hepatic function.

Please note that the recommendations for empirical therapy in hospital do not apply to children and neonates.

Clostridium difficile and high risk antibiotic agents

The '4C' antibiotics (clindamycin, ciprofloxacin and other quinolones, co-amoxiclav and the cephalosporins, especially third generation) are associated with a higher risk of Clostridium difficile infection.  The use of these agents has been restricted to try and reduce the rate of this infection by 50% in line with the Scottish Government HEAT target.  These agents are therefore not recommended as first-line treatments for common primary care infections.  There may be situations where these are the most appropriate antibiotics to give, and should only be prescribed after careful consideration of the risks and clinical benefit of prescribing.  Specific consideration should be made to using these agents in patients over the age of 65 years who are particularly at risk of the development of this infection.

Further Reference Sources

Prescribers should refer to the BNF ( Link opens in new, BNF for children ( Link opens in new window or the manufacturers' summary of product characteristics ( Link opens in new for further information. 

For information on the use of antibiotics in pregnant or breastfeeding women, or in patients with renal or hepatic impairment, please refer to BNF (information in individual drug monographs), or contact Medicines Information (Tel: 01224 552316).
Where the suggested antibiotic choices are not suitable, prescribers are encouraged to follow guidance in any of the references indicated in the text for further treatment options (national evidence based guidelines).
Please also note the recent MHRA advice for the use of cough and cold preparations in children if advising on self care Link opens in new windowMHRA guidance on the use of cough and cold medicines in children.