Pharmacists can help patients select the right needle, ensuring a comfortable and effective injection experience. Helping your patient select the right needle size is also important to reduce the risk of accidentally administering insulin or other diabetes medications intramuscularly.

For most adults using injectable diabetes medications, shorter needles (4 mm to 6mm) are appropriate and should be recommended.^5,6 The Forum for Injection Technique (FIT) guidelines recommend injection using these shorter needle lengths to minimize the risk of unintentional intramuscular administration.

When using a 4 mm, 5 mm, or 6mm needle, the average adult patient should administer the injection perpendicularly (at a 90-degree angle) to the skin surface.^5,6 For the average patient using shorter needle lengths pinching the skin to create a skin lift is typically not necessary. However, pharmacists should be aware of a few notable exceptions.  To prevent intramuscular administration (IM), very lean adults may be required to pinch the skin even when administering injections using shorter needle lengths. If a skin lift is not used, very lean adults using 6 mm needles may be required to administer the injection at a 45-degree angle to ensure subcutaneous administration.

In children and adolescents, insulin pens are typically the preferred injection device of choice due to the shorter needle size used with these products (4, 5 or 6mm). In most children and adolescents, a 4mm needle can be gently administered at a 90-degree angle without a skin lift. Leaner children or adolescents using larger needles (5 mm or 6mm) should administer the injection at a 45-degree angle using a skin lift.^5,6

Regardless of age, needle size, or gauge, patients should be trained to let the needle enter the skin gently. Pharmacists should inform patients that excess force is not required when administering the injection and can be potentially dangerous since excess force increases the risk of an IM injection. A good rule of thumb is that if a dent in the skin is formed due to application pressure, then the patient is applying too much force.

Patients who consistently apply too much force may be offered non-posted (contoured) pen needle designs. Contoured needles have the advantage of reducing the impact of unintended application force compared to other options.⁵ Applying too much injection force can lead to patients injecting into the muscle, which is associated with variable blood sugars⁷ .

Why is it important for pharmacists to ensure that patients have an adequate supply of pen needles?

When people with diabetes used proper injection technique, including using a new needle for every injection and shifting to a 4 mm or 5 mm needle, A1C was reduced by 1.0% in only 6 months^8.. Providing an adequate supply of pen needles can also limit the reuse of pen needles by patients. Pen needle reuse is associated with increased pain and bleeding⁹, lack of sterility⁹, and development of Lipohypertrophy, which can lead to erratic insulin absorption, increased glycemic variability and unexpected hypoglycemia⁵. A best practice on injection technique is to remind patients to use a new needle with every injection and ensure that they have an adequate supply of pen needle.

Pharmacists are armed with the knowledge and training to empower patients with the skills they need to navigate the challenges of injections. Interventions by pharmacy professionals to provide injection training and needle selection can give patients the confidence to reclaim control over their diabetes management. By addressing common injection errors and providing tailored guidance, pharmacists can make a significant difference in the lives of individuals living with diabetes, one injection at a time.