Insulin is a pancreatic hormone, regulating metabolism and lowering blood glucose levels. First used in 1922 to treat diabetes, insulin is still prescribed mostly for patients with type 1 diabetes but the number of type 2 diabetes patients using insulin is estimated to see a two-fold increase globally by 2030. An estimated 3.8 million people in the UK have a diagnosis of diabetes. Type 2 diabetes (where the body becomes resistant to insulin or does not make enough insulin) accounts for around 90 per cent of cases and type 1 (where the pancreas produces little or no insulin) for 8 per cent. Access to safe and effective treatment, including insulin, is critical to managing diabetes, reducing the risk of preventable complications and improving patients’ quality of life.

The dosing complexity, variety of formulations, and similarities in the names and packaging of insulin products all have the potential for errors and insulin-related harm to occur. The three main types of error – using the wrong insulin product, omitted or delayed insulin dose, and wrong insulin dose – accounted for 60 per cent of 16,600 insulin-related adverse drug events reported in the UK between 2003 and 2009. One in four resulted in patient harm. Incidents occurred at all stages of the medication process with 17 per cent prescribing errors and 10 per cent dispensing errors.

Key facts

• Insulin requirements usually increase during illness or infection
• Multiple daily injections (basal-bolus regimen) is the regimen of choice for adults with type 1 diabetes
• Dispensing and administration errors can occur where the dose is misread as a result of inappropriate use of abbreviations (‘u’ or ‘iu’ rather than ‘units’)
• Similarities in names and packaging contribute to the potential for error
• Insulins should be prescribed by brand name as different brands have different strengths and different instructions for use
• There is variation in the duration of action, peak time and onset of action between different insulins. If a patient is administered the wrong insulin, their blood glucose could become too low or too high with potential for severe harm
• People with diabetes receiving insulin therapy must be given appropriate information about how to recognise and manage hypoglycaemia
• They should also be informed about the ‘sick day rules’.