NHS Greater Glasgow & Clyde Area Drug and Therapeutics Committee
Greater Glasgow and Clyde Medicines
Medicines Update Acute

PostScript Acute 13 (October 2013)

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Gentamicin & vancomycin: update

 

Gentamicin and Vancomycin (GaV) LearnPro Module

NHS Education Scotland (NES) in conjunction with the Scottish Antimicrobial Prescribing Group (SAPG) have recently launched a new LearnPro educational package which covers gentamicin and vancomycin use.
 
This resource is based on the 2013 SAPG gentamicin and vancomycin guidance which is consistent with NHSGGC guidance.  There are 3 modules available to NHSGGC staff: 

  • Gentamicin (GGC)
  • Vancomycin (intermittent infusion)
  • Vancomycin (continuous infusion)

 

Each module provides an overview of the guidance and key points to remember when prescribing, administering or monitoring these high risk medicines.  They include a demonstration of how to calculate initial doses using the online calculator or manually using the tables.  The theory is then followed by a variety of case studies.  Case study 1 is compulsory and the pass mark is 100%.  The remaining case studies are available for extra learning and each case focuses on a specific scenario that could occur in everyday practice.

The NHSGGC Antimicrobial Utilisation Committee support the introduction of these modules within the Board.

Healthcare professionals involved in the use of gentamicin and vancomycin are encouraged to complete the modules as part of their CPD.  The modules can be accessed via the usual LearnPro https://nhs.learnprouk.com link on StaffNet. 

 

Gentamicin Prescription Chart

Slight amendments to the current gentamicin prescription chart have been agreed by the Antimicrobial Utilisation Committee. 

The main change is the introduction of space to record creatinine concentrations.  The printers will change to the updated version in the near future. Stock of existing charts can be used up and then the new versions will be implemented as part of routine ordering processes.

 

Vancomycin Prescription Chart

A short life working group is being convened to discuss the implementation of a new vancomycin prescription chart across NHSGGC.  The aim is to implement a new chart by end 2013 / early 2014.

Learning from incidents

Vancomycin accumulation due to renal failure

This case demonstrates that vancomycin will accumulate if a patient’s renal function deteriorates and doses are not reviewed.

Vancomycin was initially commenced as per GGC guidelines. The patient was prescribed an appropriate maintenance dose every 12 hours.  The GGC guidance states that the first vancomycin blood concentration should be measured (pre-dose) within 48 hours of starting therapy.  A blood sample was taken within this time limit (18 hours after the previous dose) and the dose was increased by 50%.  This was an appropriate increase but ideally the blood sample should have been a trough sample (12 hours post dose in this case).

Creatinine levels were measured daily and the table below shows how quickly renal function deteriorated:

Day of vancomycin therapy

Creatinine (micromol/L)

Change in creatinine in 24 hour period

1

69

baseline

2

52

25%  ↓

3

54

4%   ↑

4

102

89%  ↑

5

236

131% ↑

6

360

53%  ↑

GGC guidelines recommend that vancomycin levels are checked every 2-3 days or daily if renal function is unstable. Despite deteriorating renal function, a vancomycin level was not checked again until day 6.  The vancomycin trough concentration was 66.9 mg/L (therapeutic trough range is 10-20 mg/L) and the antibiotic was discontinued.

Key prescribing messages:

  • Vancomycin maintenance dose requirements depend on renal function.
  • Patients receiving vancomycin must have daily monitoring, recording and review of renal function.  This includes checking creatinine daily and comparing against previous values.
  • Vancomycin concentrations should be checked immediately pre-dose.
  • Always check that the dosage history and sampling time are appropriate before interpreting the result.
  • Vancomycin will accumulate if renal function deteriorates and doses are not reviewed (this case demonstrates how quickly this can occur).
  • If renal function is unstable monitor vancomycin levels daily.
  • If renal function deteriorates, withhold vancomycin and check the concentration.
  • If your patient has deteriorating renal function and high vancomycin levels contact a Renal Specialist for advice.  Microbiology or an ID physician will also be able to advise on alternative antibiotic therapy.
  • Document ALL action taken in the medical notes.
  • The Therapeutics Handbook outlines the full vancomycin dosing guideline.  In addition, Pharmacy is available for advice (including out of hours).

Remember…

If renal function has deteriorated, review ALL prescribed medicines and consider:

Should each medicine be continued?

  • Is it nephrotoxic?  Examples of commonly prescribed nephrotoxic drugs include; gentamicin, vancomycin, NSAIDs and ACE Inhibitors.

Is the medicine renally excreted?

  • Does the dose or dosage interval need changed?

TrakCare: Changing the IDL

TrakCare is now used across all Acute sites to create the Immediate Discharge Letter (IDL).  This is the first in a series of articles outlining ‘good practice points’ for safe prescribing on TrakCare.  This article focuses on how to safely make changes to the IDL.

The IDL should be sent to pharmacy after final decisions regarding all discharge medicines have been made.  However, occasionally changes to the IDL will be required after it has been sent to pharmacy.  The following good practice points should be followed to ensure the patient receives the correct medicines to take home:

Good practice points for prescribers

For essential medication changes after the IDL has been set to ‘Requires Pharmacy Review’:

  • Update ALL relevant sections of the IDL.
  • Reset the IDL to ‘Requires Pharmacy Review’
  • Update the Kardex.
  • Telephone pharmacy regarding the change.

Good practice points for nurses

At the point of discharge:

  • Confirm with medical staff that the IDL is the final version.
  • Check the IDL against both the Kardex and the dispensed medicines.
  • Discuss any discrepancies with medical staff.
  • Change the ‘Clinical Summary Status’ of the IDL to ‘Authorised’ and print.

Remember…

Pharmacy MUST be contacted if changes are made to an Immediate Discharge Letter (IDL) after it has already been set to ‘Requires Pharmacy Review’.

Reminder:  Missed doses of clozapine

Missed doses of clozapine have been discussed in a previous edition of Postscript Acute.   As clozapine missed doses continue to be reported, a reminder of the key messages has been outlined below.

Key messages:

  • Accurate medicines reconciliation using two sources should identify all medicines a patient is taking.  The emergency care summary alone will not identify patients taking clozapine.
  • If a patient (or carer) states that they are prescribed clozapine, Leverndale Pharmacy can be contacted to confirm the current prescription (or the Mental Health Pharmacy On-call Team if out of hours). 
  • Patients admitted to an acute hospital on clozapine MUST have therapy continued unless there is a clear clinical indication to withhold.
  • Notify pharmacy (including out-of-hours) immediately if a patient who takes clozapine is admitted to your ward.
  • Transfer clozapine medication between wards or hospitals with the patient.
  • Missed doses have potential detrimental effects on mental health.
  • Potentially life-threatening side effects can occur if a patient who has missed clozapine for more than 48 hours is put back on their original dose.
  • Pharmacy in conjunction with the patient’s consultant will provide advice if a patient has not taken clozapine for more than 48 hours.

Drug Safety Updates

Recent MHRA Drug Safety Updates highlight the following safety messages:

Drug

Safety message

Diclofenac 

New contra-indications in patients with cardiac disease

Metoclopramide

New dose and duration restrictions to reduce the risk of neurological adverse effects

Nitrofurantoin

Reminder that the drug has reduced efficacy in patients with renal impairment

Ketoconazole

No longer recommended for the management of fungal infections due to the risk of hepatotoxicity

Ondansetron

New restrictions on dose and administration to reduce the risk of QT prolongation

For further information on the above, please read the September edition of Postscript and the NHSGGC Ondansetron & QT Prolongation Memo.

Omeprazole continuous infusion:  changes to the administration schedule

Omeprazole continuous infusion is recommended for patients who have undergone endoscopic haemostasis for a bleeding ulcer. Administration advice is provided in the NHSGGC Therapeutics Handbook.  Please note that this advice was changed for the 2013 edition of the handbook to reflect changes made to the national IV omeprazole monograph. 

If you are administering or prescribing an omeprazole continuous infusion please ensure you refer to the 2013 edition of the handbook (or the omeprazole IV monograph) for advice on drug concentration and rate of infusion.

Therapeutics Handbook 2013 edition: printed copies to be amended

There is an error in the Reversal of opioid-induced respiratory depression guideline (page 41).  This occurs in the second bullet point of the dilution advice.  ‘Dilute the 10 mg concentrate’ should read ‘Dilute the 2 mg concentrate’.  In addition, TOXBASE recommends a more concentrated infusion and it has now been agreed that NHSGGC advice should be consistent with this.  The Handbook team are advising the following:

  • Score out the method of preparing an IV infusion of naloxone (including the dose example).
  • Add ‘See TOXBASE or the online handbook for dilution advice’ to this section of printed handbooks. 

Instructions for amending printed copies have been issued to clinical areas and healthcare professionals.  The online version available at www.ggcprescribing.org.uk has been amended and the TOXBASE administration advice added.

Guideline news

NHSGGC Acute Care Guidelines:

SIGN  Clinical Guidelines:

 NICE Clinical Guidelines: 

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