Overview
What a Pen Does—and What It Does Not Do
An insulin pen is a delivery device that contains a specific insulin formulation in a prefilled disposable pen or a replaceable cartridge.
An insulin pen is a delivery device that contains a specific insulin formulation in a prefilled disposable pen or a replaceable cartridge. The patient dials a dose in units, attaches a needle, and injects the insulin into subcutaneous tissue. Pens are a preferred insulin-delivery option for many adults with type 1 or type 2 diabetes because they can improve convenience and dose accuracy. A pen does not make insulin interchangeable. Rapid-acting, short-acting, intermediate-acting, long-acting, and premixed insulins have different onset, peak, duration, and meal relationships. The nurse must verify the exact insulin name, concentration, and ordered units before every dose. Concentrated pens may contain insulin such as U-200 or U-300. The dose window still displays insulin units, not milliliters. Dial the prescribed number of units; do not convert the dose based on the concentration. Never withdraw insulin from a pen with a syringe. Doing so can cause major dosing errors and contaminates or damages the device.