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The impact of ready-to-use fentanyl vials

The introduction of ready-to-use fentanyl vials with integral, peelable syringe labels reduces the risk of compounding errors with this high-risk drug and releases valuable nursing time to care for critically ill patients


Gillian Cavell MSc FFRPS MRPharmS
Consultant Pharmacist, Medication Safety King’s College Hospital NHS Foundation Trust, London, UK


The introduction of ready-to-use fentanyl vials with integral, peelable syringe labels reduces the risk of compounding errors with this high-risk drug and releases valuable nursing time to care for critically ill patients


Gillian Cavell MSc FFRPS MRPharmS
Consultant Pharmacist, Medication Safety King’s College Hospital NHS Foundation Trust, London, UK


In UK hospitals, trained nurses prepare injectable medicines for administration to patients against prescriptions written by doctors. Other than parenteral cytotoxic agents, few drugs are prepared in centralised pharmacy-led aseptic units as ready-to-administer (RTA) doses. Although the preparation of injectable medicines is checked twice by two qualified practitioners, the risk of error, particularly with complex processes and potential for patient harm, is recognised.


Ready-to-use fentanyl vial showing peelable label with syringe label underneath (image courtesy of hameln)

In March 2007, the National Patient Safety Agency published a patient safety alert to promote the safe use of injectable medicines.1 The alert provided a simple scoring system for assessing the risks associated with ward-based preparation of injectable doses (Table 1). The alert recommended that high-risk injectable medicines should be provided in the most appropriate vial or ampoule sizes and that RTA or ready-to-use (RTU) injectable products should be used to minimise the risk of error in dose preparation and administration. Fentanyl infusions are included in the United Kingdom Medicines Information (UKMI) Consensus List of High Risk Injectable Medicines.2


In 2007, a survey on the use of injectable medicines in UK critical care units was conducted to identify frequently used concentrations of injectable medicines and propose standardised concentrations for use in UK hospitals.3

Results of that survey identified that 88% of 154 UK critical care units administered fentanyl by continuous infusion in a concentration of 50mcg/ml from 50ml syringes. When the same authors proposed a standardised preparation of fentanyl 2.5mg in 50ml (50mcg/ml) 91% of 113 critical care units stated that they would use that concentration.4 However, until recently, a licensed fentanyl product of the corresponding volume has not been commercially available.

Our facility
King’s College Hospital is a large acute teaching hospital in south London. There are 63 level two or three intensive care beds across four critical care units providing general critical care as well as care to patients with critical liver dysfunction.

In December 2014, we purchased a licensed product containing 2.5mg fentanyl in a 50ml vial to replace the need to use fentanyl in 10ml ampoules to prepare a 50ml syringe in critical care units. Using the vials reduces the NPSA risk score for the preparation of fentanyl 2.5mg/50ml syringes from 3 (amber) to 2 (green) as illustrated in Table 1. This supports implementation of the NPSA Patient Safety Alert, which, although originally published in 2007, remains highly relevant to practice.

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The introduction of these vials has reduced the numbers of fentanyl 500mcg in 10ml ampoules used. Figure 1 illustrates the quantities of fentanyl 500mcg/10ml ampoules issued and the quantities of fentanyl 2500mcg/50ml vials used expressed as 500mcg/10ml equivalents. This shows that the total amount of fentanyl used is unchanged but more fentanyl is being used from 50ml vials than 10ml ampoules.

Across the organisation, including four critical care units, use of the ampoules has reduced from an average of 4312 (median 4190, range 3346–5368) per month over the 17-month period prior to implementation of 50ml vials to less than 1000, a reduction of over 3000 ampoules per month.  This means that nurses need to break open 100 fewer ampoules each day to prepare fentanyl infusions.


One of the concerns of standardisation is the potential impact on cost at a time of austerity in the National Health Service in England and Wales. Fentanyl is a frequently used, low-cost injectable medicine. The additional cost associated with the use of RTU vials is small. Our overall expenditure on fentanyl 10ml ampoules and 50ml vials increased from an average of £1250 per month to £1800 per month over the first three months following the introduction of the vials. The increase of approximately £550 per month may seem large but this equates to only one to two doses of an intravenous antifungal for an average adult (based on British National Formulary5 prices for anidulafungin, liposomal amphotericin, caspofungin), a treatment cost which would be accepted and where there are no set boundaries to course length.

Dose preparation
The RTU product has advantages, over and above the modest reduction in risk score, which justify the small cost impact. We asked nine nurses for their opinion of the 50ml (50mcg/ml) fentanyl vials compared to the 10ml (50mcg/ml) fentanyl ampoules for the preparation of fentanyl 2500mcg in 50ml infusions. There was an overall consensus that the 50ml vials were preferred to the 10ml ampoules. Nurses commented that the 50ml vials were ‘easier, safer, simpler’ and ‘much easier to use than the 10ml ampoules.’ Nurses stated that the 10ml ampoules are ‘fiddly’ with ‘a higher risk of spillage and cuts.’

As a controlled drug (CD) the requirements for maintaining and documenting accurate stock balances of such a frequently used product is time consuming.  All nine nurses we spoke to stated that it was easier to make an entry into the CD register for the 50ml (50mcg/ml) fentanyl vials. Nurses stated that you ‘do not have to count as many vials and it is easier to locate due to size.’ This results in ‘less chance of medication errors’ and only ‘one entry is needed’ in the CD register. Nurses did however mention that it was ‘sometimes difficult drawing up the fentanyl due to the vacuum’ within the 50ml (50mcg/ml) vials.

Despite this, they felt that one to five minutes of nursing time is saved when preparing fentanyl 2500mcg in 50ml infusions using the 50ml (50mcg/ml) vials compared with using the 10ml (50mcg/ml) ampoules.


Peelable label is put on syringe (image courtesy of hameln)

Reduction in errors
The reduction in potential for error during dose preparation is quantified by the reduction in the NPSA risk score. The impact of the RTU product on errors in practice is more difficult to measure as errors associated with the preparation of infusions are rarely identified once the infusion has been commenced. We know of one error with the preparation of a fentanyl infusion on a critical care unit that was identified during the checking process prior to it being administered to the patient. Five 10ml ampoules of fentanyl were taken out of storage for the preparation of a syringe to contain 2.5mg fentanyl in 50ml. During the final check it was noticed that an ampoule of noradrenaline had been mixed up with the fentanyl ampoules and incorporated into the contents of the syringe. The syringe was discarded and the dose remade. This type of mix up cannot happen if single 50ml vials are used to prepare a dose instead of multiple 10ml ampoules.

The introduction of RTU vials of fentanyl has had a positive impact on practice with limited impact on cost. The use of RTU products instead of ward-based dose preparation is in line with national guidance for safe use of medicines. The long shelf-life of vials is an advantage over pre-filled syringes, which have a shorter shelf life making wastage more likely. The presentation of drugs in vials allows for clear, well designed labels to ensure correct product recognition. This product has recently been enhanced further with the addition of an integrated peelable label to be transferred from the manufactured vial to the prepared dose in the syringe. This replaces the need for handwritten syringe labels and ensures that the contents of prepared syringes will be easy to recognise during administration as well as during dose preparation.


We believe that the advantages of using this product in terms of CD storage and convenience in syringe preparation, releasing valuable nursing time to care for our most ill patients, and complying with national guidance for safe use of injectable medicines outweigh the small financial impact of purchasing a RTU product.


Medication safety pharmacists should be involved in sourcing and promoting the use of new drug presentations such as this and should use their knowledge of the way drugs are handled at ward level to influence the products purchased for use within their hospitals. Where risk assessments and evaluations of new products have been conducted, these should be shared with colleagues via online networks


Key points

  • Fentanyl is a controlled drug used in intra-operative analgesia administered either by successive intravenous injections or by intravenous infusion.
  • Ready-to-use vials of fentanyl have had a positive impact on practice with little impact on cost.
  • Use of the vials reduces the NPSA risk score for the preparation of fentanyl 2.5mg/50ml syringes from 3 (amber) to 2 (green).
  • Nurses find use of the ready to use vials easier, safer and simpler than the 10ml ampoules.
  • Medication safety pharmacists should use their knowledge of handling of drugs at ward level in promoting the use of similar drug presentations.



  1. National Patient Safety Agency. Patient Safety Alert 20. Promoting safer use of injectable medicines. London 2007. (accessed April 2017).
  2. UKMI. Consensus List High Risk Injectable medicines. Version 2. November 2013. (accessed April 2017).
  3. Borthwick M et al. A survey to inform standardisation of intravenous medication concentrations in critical care. J Intensive Care Soc 2007;8:92.
  4. Borthwick M et al. Towards standardisation of drug infusion concentrations in UK critical care units. J Intensive Care Soc 2009;10:197–200.
  5. Joint Formulary Committee. British National Formulary. 68. ed. London: BMJ Group and Pharmaceutical Press; 2014.

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