PDL is aware of multiple instances where a pharmacist has not realised a prescription needs to be compounded. This may be due to misinterpretation of the prescriber’s intentions or assumption that the strength prescribed is an error and a proprietary product is supplied instead of the item ordered. Vigilance is always required when dispensing all items and assumptions should never be made.
Accuracy is also required whenever compounding medicines, particularly for those medicines prescribed in micrograms. Members of the Australian Society of Compounding Pharmacists (ASCP) are aware of several serious errors involving compounding of clonidine suspension for children. In some cases, these incidents have resulted in hospitalisation including rare cases of fatalities.
Clonidine is an alpha-2 adrenergic agonist with its main therapeutic use being treatment of high blood pressure. The commercially available tablets are available in 150 microgram and 100 microgram strengths.
Compounding pharmacists are often requested to compound clonidine suspension for children who are being treated for attention deficit hyperactivity disorder (ADHD) because there is no commercial suspension available.
In more than one case, the child became unresponsive and was taken to hospital with suspected clonidine toxicity.
The main areas of error include:
- A poor understanding of the strength required for the patient – both prescribers and pharmacists may be unclear that dosing is in micrograms and may inadvertently transcribe details as milligrams
- No Master Formulation Record for the compound – pharmacists should note there is no standard APF formula
- Incorrect calculations of triturations
- Confusion when preparing triturations – pharmacists are encouraged to use raw clonidine powder rather than commercial tablets which may impact homogeneity of the final preparation
- Incomplete worksheets
- Preparations made by staff with little or no formal compounding training
- Lack of counselling of parents about potential side effects which may suggest toxicity e.g. extreme sedation and optimal use of the preparation e.g. Shake the Bottle ancillary label
Following investigations in some of these cases, the clonidine preparations had a potency of well over 70 percent of the labelled strength.
Pharmacists who receive prescriptions for clonidine suspension are advised to strongly consider whether they have the appropriate training and understanding before proceeding to compound. If not, they should refer the patient on to another suitably qualified compounder.
Pharmacists are advised to pay close attention to formulation (in particular the strength of a trituration required), have calculations double-checked by a colleague or secondary compounding pharmacist where possible, and have appropriate counselling materials available to discuss with parents and carers.
Clonidine dosing is microgram based and compounders should be extremely vigilant when checking their calculations. Any prescription which is not written with microgram dosing must be queried.
Pharmacists are encouraged to have a Standard Operating Procedure (SOP) for the compounding of high-risk preparations such as clonidine to minimise error and ensure patient safety.
This alert was written by the Australian Society of Compounding Pharmacists (ASCP) in collaboration with PDL.
For immediate advice and incident support, call PDL on 1300 854 838 to speak with one of our Professional Officers. We are here to support our pharmacist members 24/7, Australia-wide.