Injector pen

First introduced in the 1980s, injector pens are designed to make injectable medication easier and more convenient to use, thus increasing patient adherence.

Many other medications are also available as injector pens, including other injectable medicines for diabetes, high cholesterol, migraine prevention, and other monoclonal antibodies.

After a slow uptake in the United States, injector pens have surpassed vial and syringe administration of insulin in type 2 diabetes.

The primary goal of injector pens is to increase patient adherence by making it easier and more convenient for people to use injectable therapy.

[2] Injector pens may also remove stigma or fear around the use of injection medication in public environments, such as insulin before a meal at a restaurant.

[3] The reduction in number of injections required may decrease the risk of non-adherence due to forgetfulness or unwillingness to self-inject medication.

[3] An injector pen consists of a chamber or cartridge of medication, a tip to attach a needle, and a piston or plunger to inject the dose.

[2] Injector pens designed for single use may also be autoinjectors, which do not require the user to press a plunger to inject the dose.

Pen needles generally do not require pinching of the skin for proper administration, unlike historically used syringes.

[9] Pen needles should be disposed of properly after each use, preferably in a purpose-made sharps container, to prevent injury from accidental contact after use.

[9] Injector pens are an alternative to the manufacture of medication for injection in vials containing either liquid or a powder to which a diluent such as sterile water is added.

[11] Combination products are available in fixed-dose ratios and are generally dosed by units of insulin, which will administer a proportional amount of the GLP-1 agonist as well.

[19] Multiple studies have shown that many people prefer the use of injector pens over other forms of injectable medication, such as vial and syringe.

[23] Another administration problem which may impact effectiveness of an injector pen is lipohypertrophy of the subcutaneous tissue near the injection site.

A major barrier to adoption in the United States was the increased up-front cost of insulin pens compared to traditional injections.