Insulin Pen Devices – Their Time Has Come

Blood glucose control is critical for diabetic patients because every major study published has shown convincingly that lower hemoglobin A1c (HbA1c) equals a reduction in diabetes-related complications.  For most patients though, the only way to prevent or minimize these complications is to use insulin therapy because of the progressive nature of type 2 diabetes.

For decades, insulin was delivered only via vials and syringes with larger bore needles that caused a lot of pain. Many people with diabetes still believe that these needles are still large and painful, but this could not be further from the truth.

There are numerous reasons why using insulin pen devices make a whole lot of sense. Compliance with treatment is better because an insulin pen device is easier to carry around, easy to use, provides greater dose accuracy, and is more satisfactory to patients as compared with a syringe. Injecting with devices makes the process discreet, and the overall cost of managing diabetes is also reduced.

One of the major drivers for adoption of insulin pen devices in institutional settings has been this cost reduction and much of this comes from the reduced need to dispose of insulin that must be discarded.  Once a vial or pen device is used for the first time, any insulin remaining after a certain number of days must be discarded.  The number of days is determined by stability testing conducted by the manufacturer and varies from 28-42 days.  Pen devices offer the advantage that they only contain 300 units per pen compared to 1000 units for the typical 10ml vial.  If a patient uses less than 30 units of insulin per day, they will typically need to discard insulin.

Advantages of Pens over Syringes

1. The current disposable pens are easy to teach
2. Using 30/31-gauge short needles with pens has significantly reduced the needle phobia that patients have about taking injections. The reason why these needles are less painful is that they do not have to be inserted into a vial first (thereby destroying the fine coating on the tip, hence the pain on injection).
3. Another important advantage of pen devices is their portability and their ability to be used discreetly.
4. Pen devices have been shown to be more accurate than syringes for the delivery of doses of insulin ≤5 units including mealtime doses
5. Older patients with diabetes may have visual impairment and/or impaired motor skills that may exacerbate the difficulties of self-injection and increase the risk of dosing errors.  Indeed, studies suggest that insulin preparation by elderly patients is highly inaccurate in one study in patients >60 years, the insulin dosage became less accurate as age increased, such that two-thirds of patients >75 years were found to be injecting the wrong dose.

Source:   Asamoah, E  Insulin Pen—The “iPod” for Insulin Delivery (Why Pen Wins over Syringe)  Diabetes Sci     Technol. Mar 2008; 2(2): 292–296.