A review and update of the standard batch sheets for oral liquid formulations compounded in New Zealand (NZ standard oral formulations or NZSOF) has been completed.
NZSOF are required to ensure consistent and best evidence-based information is available for pharmacists compounding these preparations and that the same strength is prepared across all health sectors to prevent medicine dosing errors occurring due to mix-ups. There have been several instances of overdosing and underdosing occurring due to confusion caused by different strengths being prepared by different pharmacies.
The review was performed by the compounding working group, a sub-committee of the Health Quality & Safety Commission’s medication safety expert advisory group. The compounding working group is made up of a group of pharmacists with an interest in compounding, particularly for children. Many others also gave input (details below).
The review process included:
- updating formulas according to the latest literature
- consulting with the sector to ensure the strengths of the NZSOF are appropriate and applicable in practice
- clarifying issues relating to application of storage
- expiry dates
- substitution of bases
- restyling of the batch sheet.
A more robust review and quality assurance process for the documentation was also introduced. This will be followed by a cycle of regular updates to ensure the NZSOF always remain relevant and up to date.
The NZSOF are based on the best available evidence from recent or robust published studies. In situations where such evidence is weak or unavailable the recommendations are based on current best practice from New Zealand or overseas. The review process has identified several situations where stability studies are required to improve the evidence; the compound working group is currently scoping these research projects, which will be part of ongoing work to ensure compounded oral medicines are as effective and safe as possible.
As well as ongoing review and revision, the next stage of the project is to identify those medicines that pose the highest potential risk. For example, the risk of precipitation in a medicine with a low margin of safety in overdose. The outcome will be advice on risk management strategies and lobbying for the sourcing and funding of commercially available preparations that are generally safer.
The NZSOF are hosted on the Pharmaceutical Society of New Zealand website (link) which also has supplementary information, frequently asked questions and details on how to provide feedback and ask questions. The NZSOF will also be linked from the New Zealand Formulary and the New Zealand Formulary for Children.
The compound working group members:
- David Woods [chair] (Best Practice Advocacy Centre, independent practitioner)
- Billy Allan (Health Quality & Safety Commission)
- Dr Sara Hanning (School of Pharmacy, University of Auckland)
- Louise McDermott (pharmacy, Canterbury DHB)
- Anh Nguyen (pharmacy, Southern DHB and WellSouth)
- Preetika Prakash (pharmacy, Waikato DHB; ex Auckland DHB)
- Marinda van Staden (pharmacy, Waikato DHB)
- Jovan Krstik (pharmacy, Counties Manukau DHB)
Dr Desiree Kunac (NZ Pharmacovigilance Centre), Dr Chloë Campbell (Pharmaceutical Society of New Zealand) and Pam Duncan (Pharmacy Council of New Zealand) also advised and assisted.