With the introduction of the TRESIBA (insulin degludec) U-200 pens comes a chance for dosing errors. A pharmacist recently reported that a physician prescribed 25 units daily of Tresiba U-200. This product is only available in the Novo Nordisk Flex-Touch insulin pen. An odd numbered dose is not possible with U-200 because the pen only allows dosing increments in even numbers, starting at 2 units and going up to 160 units. In this case, an elderly patient tried to dial 25 units by estimating the proper position between 24 units (marked on the pen) and a notch or score that represents 26 units (Figure 1). Due to the design of the pen, the insulin will not be administered unless the pen is correctly set to a dose—24 or 26 units in this case. It’s important for healthcare professionals to be aware of the difference between U-100 pens and the U-200 Tresiba pen. Although the U-200 pen WILL allow doses from 2 to 160 units (in even numbers only, 2 units at a time), prescribers should consider providing a U-100 pen when smaller or odd numbered doses must be administered, reserving U-200 pens for patients requiring larger, even-numbered doses.
Image: Tresiba U-200 pen allows dosing increments of 2 units, so only even numbered doses can be delivered. (www.ismp.org Institute for Safe Medication Practices)