Rationale and key points

This article provides a step-wise, practical approach to undertaking oral medicines calculations for tablets, capsules and liquid preparations. It also explores the evidence base behind medication errors in relation to calculations.

•  Medication errors have been identified as one of the most frequent types of patient safety incident that occur, and they are the most common, single preventable cause of adverse events.

•  Undertaking a medicines calculation can reduce the risk of an incorrect medicines dose being administered to the patient, which would result in a suboptimal therapeutic benefit or possible harm to the patient.

•  Nurses must ensure that they practise undertaking medicines calculations, while healthcare organisations have an important role in ensuring this skill is developed and maintained among their staff.

Reflective activity

‘How to’ articles can help to update your practice and ensure it remains evidence-based. Apply this article to your practice. Reflect on and write a short account of:

1.  How this article might improve your practice when undertaking oral medicines calculations.

2.  How you could use this information to educate nursing students or your colleagues on the appropriate methods for undertaking oral medicines calculations.