Choosing an insulin delivery device
Insulin is the mainstay of diabetes therapy. Multiple preparations of insulin are available , which can be used in various regimes. A variety of delivery devices and delivery aids are available which can be used for the administration of insulin (Tables 1 and 2) [2, 3, 4]. Although detailed emphasis is laid on the choice of insulin regimes and preparations, not much attention is paid to the choice of a delivery device.
Table 1. Classification of insulin devices
|Type||Device and manufacturer|
|Vials and syringes: 40 U/mL|
• Huminsulin preparations 10 mL
|Vials and syringes: 100 U/mL||• Apidra (Glulisine) 10 mL|
• Humalog (Lispro) preparations 10 mL, 3 mL
• Humulin preparations 10 mL, 3 mL
• Novorapid/Novomix 10 mL
• Novolin preparations 10 mL
• Lantus 10 mL
• Levemir 10 mL
|Vials and syringes: 500 U/mL||• Humulin R 20 mL|
|Pens: Disposable (prefilled)|
• Kwik Pen (Eli Lilly)
|Pens: Durable (reusable)||• HumaPen Ergo (Eli Lilly)|
• HumaPen® Luxura (Eli Lilly)
• Humapen savvio (Eli Lilly)
• Humapen Memoir (Eli Lilly)
• AutoPen Classic (Sanofi)
• NovoPen 4 & 5 (NovoNordisk)
|Injection assist devices||• Trulicity pen (Eli Lilly)|
Table 2. Injection assist devices
|Site selection||TARTOOS||Visual Medical|
|Learning toy||JERRY THE BEAR||Sproutel|
|Needle safety||SECURITEE BLANKET|
INJECTION SAFETY GUARD
Supply Storage DIASECURE
|IntraPump Infusion Systems|
Bionix Medical Technologies
Importance of choice
The process of choosing an insulin delivery device is an important one. The delivery device may impact patient acceptance of, and satisfaction with, insulin therapy . This affects adherence to prescribed therapy. Accuracy of dose is also affected by choice of delivery device, which may modulate ability to inject at the appropriate (subcutaneous) site . Thus, by multiple means, insulin delivery devices impact glycemic control. All delivery devices have to be approved by regulatory authorities prior to marketing. Published evidence is available to back the use of all available delivery devices. All these devices demonstrate adequate efficacy/accuracy, safety and tolerability and, in general, modern delivery devices are found to be more accurate and easier to use than vials and syringes [7, 8, 9].
Opportunity for choice
As most delivery devices are manufacturer-specific and product-specific, the choice of a device is usually a secondary decision, made after the insulin regime has been decided. Also, in many healthcare setups, there may be a limited variety of devices available. At times, however, the delivery device may help choose one preparation over another (Table 1). When a rapid acting insulin or premixed insulin has to be prescribed, for example, the characteristics and advantages of the delivery device associated with each insulin analogue may play a role in shared decision-making. The same is true when once-weekly glucagon-like peptide-1 receptor agonists (GLP-1RA) or co-formulations of GLP-1RA with insulin have to be chosen.
Factors determining choice
The choice of a delivery device depends upon various clinical and patient factors, as outlined below and in Table 3. While accuracy can be taken for granted in an approved delivery device, there do exist subtle differences, which can play a role in decision making [7, 8].
Table 3. Factors in choosing a delivery device
• Length of needle
• Degree of dose increment
• Suitability for children/visually/dexterity-challenged persons
• Comfort/ease of use
• Ease of transport/storage
• Temperature stability
• Biodegradability/“green devices”
• Availability of compatible insulins
• Availability of ancillary supplies
• Cost of device
• Cost of insulin refills, needles
• Expected duration of insulin therapy (with prescribed regime)
• Monthly dose requirement (vis a vis capacity of device)
|Medication counseling factors|
• Time taken to teach (TTT)
• Time taken to learn
• Risk of error in delivery
• Availability of post-prescription follow-up
The degree of dose increments possible is an important factor in such decision-making. Children, persons with brittle diabetes, and those with very low requirements will require a delivery device that allows changes of half or one unit at a time, as opposed to those that provide increments/decrements of only two units.
Most manufacturers suggest that vials and pens should be discarded after 28 days of use . A person with low insulin requirement, therefore, should choose vials or cartridges which contain lesser quantity of insulin.
Persons with visual impairment or limited manual dexterity will require pens which offer large sized visual display of dose, audible clicks when dose is dialed, and push buttons which need less force to push [10, 11, 12]. Newer pens in development include features such as time and strength of last administered dose, which are important for persons with impaired memory.
Psychosocial factors, such as attractiveness of the pen, which is decided by its size, color, and discreteness, also play a role in choice of delivery devices . Personal choice should be taken into account wherever possible. For persons who travel frequently, for example, ease of transport can be an overriding issue. For others, color of the pen may be the deciding factor.
Similarly, stability in extremes of temperature may be the main consideration for persons who live in or travel in such climates. Biodegradability and carbon print of devices are deciding factors for those who believe in the concept of green diabetology .
Duration of therapy
Pragmatic limitations, however, usually inform the choice of a delivery device. Expected duration of insulin therapy in general, and a particular insulin regime in specific, plays a significant role in device choice. Short-term insulin therapy is better managed with disposable devices, while long term treatment may encourage use of reusable or durable devices.
Cost of the device [14, 15], its insulin preparation, and its ancillary supplies (such as needles) are extremely important, especially in pay from pocket markets. So too is the availability of insulins compatible with the device. In a patient who may require a change of insulin regimen in the near future (eg, intensification from basal to premixed insulin, or de-escalation from basal bolus to basal insulin), one should choose either disposable devices or durable devices which are compatible with multiple preparations.
Time to teach
So far we have discussed decision-making in patient-centric terms. The diabetes care professional (DCP) who demonstrates and teaches use of the delivery device should be considered while deciding insulin delivery devices. The DCP’s comfort with a particular device, the time taken to teach (TTT), and ability to provide post-counselling follow-up should be taken into account [16, 17]. In a busy practice, for example, TTT becomes extremely important. It takes less time, for instance, to explain the use of disposable pens as compared to durable pens, which in turn are easier to demonstrate than vials and syringes.
Take home message
A process of shared and informed decision-making, facilitated by demonstration, helps ensure that the right delivery device is chosen and prescribed for persons who require insulin.
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