Prescription Writing for Tresiba FlexTouch 100 unit/mL, 54 Units Daily, 90-Day Supply
For a 90-day supply of Tresiba FlexTouch 100 unit/mL at 54 units daily, prescribe 5 pens (each pen contains 300 units), which provides approximately 28 days per pen, totaling 140 days of supply—sufficient to cover the 90-day period with appropriate buffer.
Prescription Details
Write the prescription as follows:
Medication: Tresiba FlexTouch 100 units/mL (insulin degludec)
Dose: 54 units subcutaneously once daily
Quantity: 5 pens (each pen = 300 units)
Days Supply: 90 days
Refills: As appropriate
Calculation Breakdown
- Daily requirement: 54 units/day
- 90-day requirement: 54 units × 90 days = 4,860 units total
- Units per pen: 300 units (Tresiba FlexTouch 100 unit/mL pen)
- Pens needed: 4,860 ÷ 300 = 16.2 pens
However, pens are dispensed in whole units, so round up to 17 pens for a true 90-day supply. Most insurance plans and pharmacies will accept either 5 pens (approximately 28 days supply) dispensed monthly, or you can write for 17 pens for the full 90-day supply if the patient's insurance allows 90-day fills.
Important Prescribing Considerations
Pen Selection
The Tresiba FlexTouch 100 unit/mL pen delivers 1 to 80 units per injection in 1-unit increments 1. Since the patient requires 54 units daily, this pen is appropriate (the U-200 concentration pen would also work but delivers in 2-unit increments, which is less precise for this dose).
Storage and Handling Instructions
- Unopened pens: Refrigerate until expiration date
- In-use pens: May be kept at room temperature (below 86°F/30°C) for up to 56 days after first use 1
- Instruct patients to discard pens 56 days after first use, even if insulin remains
Critical Patient Education Points
Dosing accuracy: The dose counter on the FlexTouch pen shows units directly—no dose conversion is required 1. Patients must never use a syringe to withdraw insulin from the FlexTouch pen 1.
Injection technique:
- Rotate injection sites within the same anatomical region (abdomen, thighs, or upper arms) to prevent lipodystrophy and localized cutaneous amyloidosis 1
- Never inject into areas with pits, thickened skin, lumps, or damaged tissue
Timing flexibility: While Tresiba should be taken once daily, adults have flexibility in timing. If a dose is missed, take it as soon as remembered, but ensure at least 8 hours between doses 1. This flexibility is unique to insulin degludec due to its ultra-long half-life of approximately 25 hours 2, 3.
Common Pitfalls to Avoid
Do not confuse U-100 and U-200 concentrations: Both deliver the same number of units, but U-200 is more concentrated. The dose counter always shows units, not volume 1.
Needle disposal: Patients must use a new needle for each injection and dispose of used needles in a sharps container—never recap needles due to needlestick injury risk 1.
Hypoglycemia monitoring: Educate patients on hypoglycemia symptoms (dizziness, confusion, sweating, shakiness) and ensure they know to check blood glucose levels regularly 1.
Drug interactions: Warn patients that thiazolidinediones (TZDs) combined with Tresiba may cause or worsen heart failure 1.
Insurance and Practical Considerations
Most insurance plans prefer 30-day supplies dispensed monthly (5 pens per month) rather than a full 90-day supply upfront. Verify the patient's insurance formulary coverage and prior authorization requirements, as basal insulin analogs like Tresiba may require step therapy or prior authorization compared to older, less expensive options like NPH insulin 4.