How to contact Microbiology / Infectious Diseases / Pharmacy

Galway University Hospital (GUH)


  • Consultants: Prof. Martin Cormican via switch, Dr. Úna Ní Riain 3779, Dr. Deirbhile Keady/ Dr. Eithne McCarthy 2013, Dr. Teck Wee Boo 3783, Dr. Dimitar Nashev 8371, Dr Ruth Waldron 4146 (or through the hospital switch board)
  • Microbiology Registrars: 4573 / 2643

Infectious Diseases (ID)

  • Consultants: Dr. Catherine Fleming 2210, Dr. Helen Tuite 2210, Dr. David Gallagher 3722 (or through the hospital switch board)
  • ID Registrar Bleep 671, SHO Bleep 814


  • Consultant: Dr. Edina Moylett 4654


  • Antimicrobial Pharmacists: Ms. Orla Fahy 2150 Bleep 503, Ms. Katie McDonough Bleep 629
  • Pharmacy dispensary UHG: 4651 / 4205  Merlin Park: 5682 / 5378

GUH Out of Hours:  A Consultant Microbiologist is on call 24 hours per day 7 days per week and can be contacted through the hospital switch board. In general, out of hours, the Consultant Microbiologist should be contacted by the appropriate Registrar or Consultant.

Mayo University Hospital (MUH)

  • Microbiology Consultants: Dr. Shomik Sibartie 1335, Dr Leonardo Nieto-Aponte  2138 (or via MUH switch board)
  • Microbiology registrar: 2137
  • Antimicrobial Pharmacist: Bleep 630
  • Pharmacy Dispensary Mayo: 2192 / 2193
  • Out of hours: Microbiology Consultant on call via MUH switch board

Portiuncula University Hospital (PUH)

  • Microbiology Consultant: via Reception in Portiuncula - 24/7 Registrar/Consultant only
  • Antimicrobial Pharmacist: Bleep 834
  • Pharmacy Dispensary Portiuncula: 8221

Roscommon University Hospital (RUH)

  • Microbiology Specialist Registrar: 091 544573 or 091 542643
  • Out of hours (or if Specialist registrars not available):See GUH Out of hours above
  • Pharmacy Dispensary Roscommon: 2279

Guideline Development Group

Development of these guidelines was led by a group comprised Dr. Ú. Ní Riain, Ms. D. Hogan-Murphy, Ms. R. Breslin, Dr. T. Boo, Prof. M. Cormican, Dr. C. Fleming, Dr. H. Tuite, Dr. D. Gallagher, Dr. D. Keady, Dr. E. McCarthy, Dr R. Waldron, Dr. D. Nashev, Dr. E. Houlihan, Dr. M. Lucey, Dr. K. Davenport and Ms. K. McDonough. The guidelines initially developed by Prof. M. Cormican in 2004 have been revised and expanded every two-three years. The guidelines are based on national and international guidelines, local microbiological data and expert opinion.

During the consultation process, contributions and suggestions were received from colleagues, including Ms. S. O Regan, Ms. Siobhan Smyth, Ms. Rose Cafferkey and Dr Shomik Sibartie. The group would like to acknowledge any others not mentioned, for contributions to preparation and review of these guidelines, particularly Marie Tierney for historical contribution. Comments or suggestions for improvement for future editions can be sent by email to Dr. Úna Ní Riain at 


The guidelines have been approved by Galway University Hospitals (GUH) Drug and Therapeutics Committee. See GUH useful resources for the most up-to-date electronic version of these guidelines.

The guidelines are available as an application for Smartphones (Apple and Android), with built-in dosing calculators for gentamicin, tobramycin and vancomycin. The GAPP App provides automatic updates to ensure access to the most recent version of the guidelines.


Effective from:    July 2021

Review Date:      July 2024       



Statement of Purpose and Limitations

This document relates primarily to common conditions or to conditions that are uncommon but associated with serious morbidity or mortality.  It is intentional that this empiric guideline document presents minimal background and explanation. 

Dosage and dose intervals as specified are for adults with normal renal and hepatic function. There is a separate section for dosing in renal impairment. Although certain specific adverse effects are referred to, issues of adverse effects, drug interactions and contraindications are not addressed in detail. They should be checked in appropriate sources such as the manufacturer’s licensed product information in the Summary of Product Characteristics (SPC) available at and the British National Formulary (BNF). 

Prescribers must use their professional judgement to identify circumstances in which there are specific reasons why this general guidance is not appropriate.  In such circumstances please discuss treatment with the Departments of Microbiology, Infectious Diseases or Pharmacy.

These empiric guidelines are designed in line with best practice in antimicrobial prescribing and with national and international guidelines on antimicrobial stewardship. As such, they support optimal antimicrobial use in GUH. Optimal antimicrobial use means that patients receive the right antimicrobial therapy at the right dose, route and duration, and for the right infection type at the right time, while minimising the risk of development of resistance.

  • These guidelines are intended for initial empiric therapy.  Empiric treatment is choice of antimicrobial prior to susceptibility results being available.
  • Regular review of the patient’s progress is essential and treatment should be reviewed in the light of changes in clinical condition. 
  • If a specific pathogen(s) is identified, the treatment should be reviewed.  The least toxic, narrowest spectrum and least expensive agent or combination of agents that is effective should be used for the treatment of specific pathogens.
  • Usual recommended duration of therapy is included for many conditions, and assumes there is satisfactory clinical progress and response to therapy – clearly if clinical progress is slow or not satisfactory then individual patient management, including the duration of therapy, should be reviewed and discussed with Microbiology or Infectious Diseases if required.
  • It may be possible to switch from IV to oral therapy after 24 to 48 hours. 
  • Please discuss duration of therapy and potential for switch from IV to oral therapy with Microbiology or Infectious Diseases or Pharmacy if required.

GUH have agreement to use the Children's Health Ireland (CHI) Antimicrobial Guidelines for patients less than 18 years old. The guidelines are available as part of the CHI (at Crumlin and Connolly) Paediatric Formulary app. The CHI website can be accessed via link . You may be asked to register an account using your email address. The lead contact is Dr. Edina Moylett.



GUH Disclaimer

The GUH Antimicrobial Guidelines (GAPP) are being shared on the strict understanding that these guidelines were prepared for use by healthcare professionals in Galway University Hospital (GUH), Portiuncula University Hospital (PUH), Roscommon University Hospital (RUH) and Mayo University Hospital (MUH) only. Any use of part, or all, of these guidelines outside of GUH, PUH, RUH and MUH is conditional on them being reviewed by appropriate clinicians /management. No liability whatsoever shall attach to GUH for the use of part, or all, of these guidelines outside of GUH, PUH, RUH and MUH.

These guidelines are intended to guide and facilitate the care of patients at GUH, PUH, RUH, and MUH. The guidance contained therein is not intended to replace individual assessment and personalised treatment of the patient. The authors have made every reasonable effort to base the guidance on best available evidence and to ensure accuracy of content at the time of going to press. However technical and clinical information changes rapidly and it is not possible to guarantee that all items will be accurate at all times. The application of the information in this guideline in clinical situations remains the professional responsibility of the practitioner.

GUH Pharmacy Resources

Access pharmacy inTERnet site at for GUH Intravenous Medicines Administration Guide. Monographs are available for all intravenous medicines, including antimicrobials, in use in the hospital. Please consult the guide for information on safe prescription and administration of intravenous medicines.

Additional information including Pharmacy reference sources e.g. Medicines Complete, BNF, BNF for Children, The Renal Drug Database are available on  inTRAnet site via hospital network computers only at http://medinfogalway/

Contact Pharmacy Department for additional information and advice (see How to contact Microbiology / Infectious Diseases / Pharmacy section above).

Changes for this Edition

Changes for this edition - Version 10: 2021 (significant changes in bold)

Prescribing Principles

  • Comment to use the Children's Health Ireland (CHI) Antimicrobial Guidelines for patients less than 18 years old and Link to CHI website.
  • Link to new interactions section. Obesity comment. Updated quinolone warning–added links from all sections where quinolone indicated.

Reserve Antimicrobials

  • Additional information added re process of pre-authorisation and supply. Amalgamation of Appendix into main section. Update of Ward poster.

Penicillin Hypersensitivity

  • Addition of risks of using alternatives to penicillin in patients inappropriately labeled allergic. Added prompts for referral to immunology

Aminoglycoside and Vancomycin Dosing and Monitoring

  • All introductions: Amended comment for discussion of patients with CrCL< 30ml/minute with Micro/ID (previously <80ml/min).
  • Table 3: if renal function is changing, recalculate dose with current creatinine.
  • Gentamicin and Vancomycin Table 1& Tobramycin Table 2: This calculator will not produce reliable results in patients who are anuric or in acute renal failure. Advice should be sought from your ward pharmacist or microbiology or infectious diseases. Details provided below for background information only. 
  • Amikacin in MDRTB – added link to IV guideline for dosing
  • Vancomycin: Calculator is suitable for patients with stable renal function. Dosing and monitoring for patients with renal impairment with creatinine clearance less than 30ml/minute should be discussed with Microbiology /Infectious Disease team on a case-by-case basis

3. Cardiovascular

  • Renamed section. Removal of comment re rifampicin from empiric treatment of Bacterial endocarditis

4. CNS

  • Bacterial meningitis: Referral to immunology strongly recommended in penicillin anaphylaxis. Referral to micro/ID essential if device-related infection.
  • Herpes Simplex Encephalitis - Refer to IV guide for aciclovir dosing in obesity

5. Eye

  • Expansion of section for Acute bacterial conjunctivitis

6. Fungal

  • Mild oropharyngeal candidiasis- extended duration (7-14 days as per IDSA)
  • Oesophageal candidiasis  - Added option of higher dose (400mg) and prolonged duration (14-21days)
  • Acute Vulvovaginal candidiasis (VVC) – Fluconazole 150mg PO first-line. Clotrimazole pessaries 500mg second-line.

7: Gastrointestinal

  • C difficile infection (CDI): Added comment re stopping the offending antibiotic and treating empirically if patient is symptomatic. Comment on Availability of vancomycin capsules on discharge. Amalgamation of Appendix 3 CDI treatment algorithm into main section. Changed heading in algorithm to ‘Non-severe’ CDI (Previously ‘Mild to moderate’).
  • Gastroenteritis: Removed treatment table. Added  comments re viral causes, pathogen directed therapy and discussing severe cases with Micro/ID
  • H.pylori: Replace esomeprazole with ‘PPI’, Added comment re previous antibiotic exposure

8: Genital system

  • PID and Acute Prostatitis/ Epididymo-orchitis –increase of Ceftriaxone IM dose from 500mg to 1g. Added IV option for inpatient Prostatitis/ Epididymo-orchitis

9: Intravascular line

  • Addition of comment to send tip of central line to lab in setting of suspected central line infection

10: Malaria

  • Updated scheduling of Riamet

11: Neutropenic sepsis

  • New dedicated section. Algorithm – added comment (to align with sepsis section): Meropenem should be considered in patients who are critically ill with sepsis or have a history of a Gram-negative Multi-drug Resistant Organism (MDRO) Discuss with Micro/ID.

12: Obstetrics

  • Link to sepsis section. Link to UTI section for acute pyelonephritis only.

13: Respiratory

  • CAP - Switched to IDSA criteria for sending sputum cultures. Updated CAP algorithm. Increased doxycycline dose.
  • Aspiration Pneumonia - Added ‘Community acquired’. Added comment Antimicrobial therapy for patients with aspiration without clinical evidence of pneumonia  (acute aspiration pneumonitis) does not offer clinical benefit
  • COPD - Increased doxycycline dose.
  • HAP –Contact Micro/ ID for treatment of Pseudomonal infection. Increased frequency of Piperacillin/tazobactam for moderate /severe HAP from every 8 hours to ‘every 6 hours’.
  • PJP - ID or micro consult recommended. Extended duration Non-HIV infected: 14 -21 days

14: Sepsis

  • Sepsis Source unclear–increased frequency of Piperacillin/tazobactam to ‘every 6 hours’. Prompt re de-escalation. Removed Neutropenic sepsis section to separate section 11.

15.Skin and Soft tissue

  • Mild Cellulitis: Addition of mastitis comment. Increase dose range Flucloxacillin to 500mg – 1g (unlicensed). Reduced Duration to 5days
  • Renamed Diabetic Foot Infection (previously Soft tissue). Added comment to refer to Diabetic Foot Team (ENDF). Minimum 7 days for mild infection. Added comment Discuss severe infections with Microbiology or Infectious Diseases. Higher doses may be indicated.
  • Bites: Addition of references to HSE immunisation guidelines for tetanus and rabies risk assessment and management; and EMI guidance for blood-borne viruses. Increased doxycycline dose. Separated durations for prophylaxis and treatment

16. Throat

  • Peritonsillar abscess-penicillin allergy - switch from cefuroxime to ceftriaxone. Dose range of clindamycin increased from 600 to 900mg.

17. UTI

  • Removal of options/duration for cystitis in pregnancy – Refer to WAC document.
  • Reduced duration for cystitis in females to 3 days. Added 7 days duration for males

18: Viral

  • Refer to STI clinic for Genital herpes. Removed dosing for severe Herpes Zoster – discuss with Micro/ID

Antibiotic prophylaxis in surgery

  • Cardiothoracic – Reduction of duration of prophylaxis from 48 to 24 hrs. Added link to Antibiotics requiring additional intra-operative doses table. Addition of TAVI section.
  • ENT and Orthopaedic – Added gentamicin as Gram negative cover in severe penicillin allergy in ENT and Orthopaedic implant procedures
  • Obstetrics/gynaecology – Added new section ‘Operative vaginal delivery’. Expanded list of procedures where SAP not generally indicated. 
  • Urology - Addition of Robotic Prostatectomy section.

Paediatric Guidelines

  • 2020 – Removed section following agreement to use Children's Health Ireland (CHI) Antimicrobial Guidelines. See Prescribing principles. Removed paediatric dosing throughout guidelines.

Renal Dosing

  • Assessing Renal function: Updated comments to match BNF. Added comment in the acutely critically ill patient with AKI, antimicrobials with wide therapeutic indices and minimal safety concerns e.g. beta lactams should/may be given at full dose for the first 24-48h. Added link to gentamicin calculator which may be used for dose adjustment for other antimicrobials.
  • Doses of Antimicrobials in Renal Impairment table: Added introductory comments. Updated renal dosing. Antimicrobials marked with an asterix have significant differences in dosing between reference sources. 
Appendix 1
  • New section Interactions - with links to interaction checkers
Appendix 3
  • Removed detail re splenectomy vaccination. Refer to national immunisation guidelines Chapter 3.
Appendix 4
  • Chemoprophylaxis for Meningococcal disease – Ciprofloxacin recommended as an option for prophylaxis as alternative to rifampicin.Dosing in children removed.
  • Chemoprophylaxis for HIb - Removal of comment chemoprophylaxis not recommended for pregnant women.




Document Version

Version 10: July 2021

Document History

Version date

Document version

Changes from previous version

Edited by


Version 1



May 2006

Version 2

Updated clinical information and compliance with new intranet publication standards


July 2006

Version 2.2

Review by pharmacy for omission errors relating to dosage ROUTES e.g. ciprofloxacin 750mg BD. Complete independent check by two pharmacists


July 2007

Version 3.1

Updated guidelines (clinical information and re-formatting) following meetings of Guideline Development Group.


March 2009

Version 4.1

Updated guidelines (clinical information and re-formatting) following meetings of Guideline Development Group.


July 2010

Version 5

Updated guidelines (clinical information and re-formatting) following meetings of Guideline Development Group.


March 2011

Version 5.1

Page 21. Updated treatment of moderate and severe CAP for patients with penicillin allergy. Levofloxacin replaced moxifloxacin as respiratory quinolone on IMB safety advice.

Page 37. Amended surgical prophylaxis in cardiothoracic surgery: pacemaker/ICD insertion. If MRSA suspected teicoplanin to replace flucloxacillin. For penicillin allergy removed gentamicin (teicoplanin & gentamicin both still indicated for pulmonary resection).


July 2011

Version 5.2

Pages 10-12. Text/layout changes for clarity

Pages 54-58. Paediatric guidelines Rev 3 2011 (Updated meningitis guidelines, added meningococcal septicaemia, MCUG prophylaxis & malaria)


July 2012

Version 6

Updated guidelines (clinical information and re-formatting) following meetings of Guideline Development Group.


June 2013

Version 6.1

Re-organised content for app development (all sections). Added disclaimer & prescribing principles. Changed CDAD to CDI. Paediatric guidelines Rev 5 (Augmentin dosing)


July 2014

Version 7

Updated guidelines following meetings of Guideline Development Group.


September 2014

Version 7.1

Paediatric guidelines Rev 6.1 (added maximum doses; modified severe malaria section)

Antibiotic Prophylaxis in Surgery: Minor formatting changes


December 2014

Version 7.2

Amended renal dosing cefTAROLine, nitrofurantoin, teicoplanin


November 2015

Version 7.3

Reserve Antimicrobials & Appendix 1: Red Light pre-authorisation Paediatric guidelines Rev 6.2 (new sections for: Sepsis in neonates admitted from home; Benzylpenicillin for confirmed Group B Strep infection; Adenitis. Updated gentamicin dosing).


July 2016

Version 8

Updated guidelines following meetings of Guideline Development Group.


March 2017

Version 8.1

Editing changes in several sections: genital (minor wording change), obstetrics (use booking weight for dosing gentamicin), sepsis (title changed to sepsis source unclear & background note 2 updated), UTI (use booking weight for dosing gentamicin and vancomycin in pregnancy).

Summary adult guidelines table updated.

Surgical antibiotic prophylaxis: added new urology procedures: transperineal prostatic biopsy & brachytherapy.  


February 2018

Version 8.2

Reserve antimicrobials – updated policy & added meropenem pre-authorisation

Penicillin hypersensitivity - updated definitions

H. pylori eradication regimens – new section



July 2018

Version 9

Updated guidelines following meetings of Guideline Development Group.

Multi-drug Resistant Organism (MDRO) definition

CPE definition


April 2019

Version 9.1

Quinolones review and inclusion of warning in prescribing principles RB/DHM/UNiR
May 2020

Version 9.2

Removal of GUH Paediatric Guidelines. Replaced with link to Children's Health Ireland (CHI) Antimicrobial Guidelines website.  RB/DHM/UNiR
July 2021

Version 10

Updated guidelines following meetings of Guideline Development Group. RB/DHM/UNiR



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