Background To determine quantity of medication discarded when giving a subcutaneous controlled drug (CD). There are multiple reviews and pledges to reduce overprescribing of medications¹ and recognising the increasing prescribing of opioids in the UK.^{2 3} There are limited reviews of the amount that is wasted from opening a vial and having to discard leftovers.

Method This data spans January 2023, collected from CD record books at Winchester Hospice, a 10 bed unit. It focused on subcutaneous morphine derivates including morphine (10 mg/ml, 20 mg/ml, 30 mg/ml), oxycodone (10 mg/ml, 20 mg/2 ml, 50 mg/ml), and alfentanil (2 mg/ml). The data recorded a patient pseudonym, the date and time of drug administration, whether medication was given as required (PRN) or as a continuous subcutaneous infusion (CSCI), the quantity given and discarded.

Results

• For PRN doses, more medication was wasted than given (60% of morphine 10 mg/ml, 70% oxycodone 10 mg/ml).

• There were multiple examples of repeat PRN’s being given at the same dose over 24 hours.

• It was only once recorded that a PRN was administered and a CSCI set up at the same time using the same vial.

• Some medications are more expensive than others (i.e. morphine 20 mg/ml, £17 a vial)

• 23% of the value of morphine derivates used in the hospice was wasted (total value of morphine derivatives given totalled £315.89; total wasted totalled £95.92)

ResultsAction: This lead to:

• Discussions with pharmacy – 20 mg/ml morphine vials discontinued due to significant cost differences and reviews if smaller vial sizes would be available (none identified)

• Discussions with the palliative team – to ensure there is a range for PRN doses and to escalate these if required, to consider whether the patient requires a PRN when setting up a CSCI and to use the same vial if so, and for prescribers to consider cost and quantities being used when prescribing.

References

1. https://www.gov.uk/government/news/government-pledges-to-reduce-overprescribing-of-medicines

2. https://www.lse.ac.uk/News/Latest-news-from-LSE/2021/l-december-21/UK-highest-consumer-of-opioids-globally

3. https://www.bmj.com/content/372/bmj.m4901