Insulin Pen Priming Recommendations
Prime insulin pens once before each injection until at least one drop of insulin appears at the needle tip to ensure proper flow and accurate dosing. 1
Rationale for Single Priming
The purpose of priming is to:
- Confirm the needle is not obstructed 1
- Ensure insulin flows freely through the delivery system 1
- Remove any air that may have entered the cartridge 1
A single prime with visible insulin at the needle tip is sufficient to achieve these goals before each injection. 1
Proper Priming Technique
When priming your insulin pen:
- Attach a new needle before each injection 2
- Dial a small dose (typically 2 units, though this varies by manufacturer) 1
- Hold the pen with needle pointing upward 1
- Press the dose button until you observe at least one drop of insulin at the needle tip 1
- If no insulin appears, repeat the priming process once more 1
Critical Safety Considerations
Never proceed with injection if priming does not produce visible insulin at the needle tip, as this indicates obstruction or malfunction. 1
Additional safety points:
- Remove and dispose of the pen needle immediately after each use 2, 1
- Never leave needles attached to pens between uses, as this allows air seepage into the cartridge and medication leakage, both of which distort dose accuracy 1
- Never share insulin pens between patients due to risk of biological contamination 1
Common Pitfalls to Avoid
Needle reuse is a frequent cause of priming failure and dosing inaccuracy. While some patients reuse needles due to cost constraints, this practice leads to:
- Blunted or misshapen needles that increase injection pain 2
- Increased risk of lipohypertrophy development 2
- Air contamination of the insulin cartridge 1
- Loss of sterility 2
If needle reuse is unavoidable due to resource limitations, evidence suggests pen needles may be used 4-5 times in the same individual without significantly increasing pain, though this is not manufacturer-recommended. 2
Additional Injection Technique Requirements
After successful priming:
- Do not touch the dose button until the needle is fully inserted into subcutaneous tissue 1
- Press the button along the pen's axis (vertically), not at an angle 1
- Keep pressure on the button until the needle is completely withdrawn to prevent incomplete dosing 1
- For insulin pens specifically, keep the needle embedded in the skin for 5 seconds after complete delivery of the dose 3