Medicines Safety Tip: Tresiba® Dosing Safety Concerns

Tresiba® is available for the treatment of diabetes mellitus in adults, adolescents and children from 1 year old and is available in two strengths — 100 units/mL and 200 units/mL containing insulin degludec [rDNA origin].

The two Tresiba® strengths are delivered in two distinct pen devices:

  • Tresiba®100 units/mL FlexTouch pen can deliver insulin in steps of 1 unit, with a maximum of 80 units per injection
  • Tresiba® 200 units/mL FlexTouch pen can deliver insulin in steps of 2 units, with a maximum of 160 units per injection

Novo Nordisk is experiencing a shortage of Tresiba® 100units/ml FlexTouch pens, which is expected to last until January 2024. This has resulted in patients being transferred to the 200 units/ml pens and has led to the MHRA and Novo Nordisk issuing a communication regarding safety concerns with dosing when switching between strengths.

https://www.medicines.org.uk/emc/rmm/2/Document

The Medication Safety Officer (MSO) network has reported at least 4 cases (in different parts of the country) where community pharmacists have made incorrect recommendations to patients regarding insulin dosing. The pharmacies appear to have apparently recommended that the patient halves their dose seemingly unaware that the pens dial up the dose and automatically deliver the correct volume. At least one of these cases resulted in harm as the patient developed diabetic ketoacidosis (DKA) and was admitted to hospital.

The devices have a dose-counter window that shows the exact dose dialled. This means that the dose that is shown in the window is the dose that will be injected regardless of strength. No dose conversion should be done when transferring patients between the two strengths.

Advice for Community Pharmacy teams

  • Double check the strength when dispensing, if in doubt contact the prescriber
  • Familiarise yourself with the products and how to dial up units so that patients can be appropriately trained in the correct use of the Tresiba® FlexTouch pen
  • Instruct patients to always check the insulin label when they receive it at the pharmacy and before each injection to avoid accidental mix-ups between the two different strengths of Tresiba®
  • Advice patients that the devices have a dose-counter window that shows the exact dose dialled and no dose conversion is necessary when switched to the higher strength pens

The packaging and the respective pens have been designed to clearly differentiate between the two strengths. The Tresiba® 100 units/mL label and packaging are light green with a graphic design on the carton. The Tresiba® 200 units/mL label and packaging are dark green with striping. The Tresiba® 200 units/mL label and packaging also have a red box highlighting the strength, see below:

Tresiba