Resuspension of insulin
Cloudy insulin must be properly resuspended before use. This is achieved by rolling the vial, cartridge or pen 10 times. Following this, it must be gently inverted 10 times before a visual check is made to ascertain that it is a uniform milky-white colour.5
Single use of needles
Most insulin needles (pen needles or syringes) are approved for single use. Therefore, they should only be used once. However, it is widely recognised that the reuse of pen needles and syringes is common in adults and children.5 There is evidence that needle reuse relates to an increased risk of lipohypertrophy. Blanco, Hernandez, Strauss and Amaya15 demonstrated a clear trend towards an increased incidence of lipohypertrophy the more times a needle was reused, particularly when the needle was reused more than five times.
The needle may become distorted and bent with reuse, and there may be loss of lubrication. This can lacerate the skin2 and result in a more painful injection.