Prescription Sig for FreeStyle Libre 3 Plus Sensor
The prescription sig for FreeStyle Libre 3 Plus sensor should read: "Apply one sensor to the back of the upper arm. Replace every 15 days. Scan sensor with reader as needed to check glucose levels."
Sensor Specifications and Wear Duration
- The FreeStyle Libre 3 Plus uses a 15-day factory-calibrated continuous glucose monitoring sensor with improved design to reduce vitamin C interference 1
- The sensor is approved for wear periods up to 15 days (360 hours) before replacement is required 1
- No fingerstick calibrations are needed as the device is factory-calibrated 2
Application Site and Method
- The sensor should be applied to the back of the upper arm 3, 2
- The device features a smaller sensor design compared to previous generations, which may improve adherence 1, 4
- Application involves inserting a subcutaneous filament less than 0.4 mm thick under the skin 2
Usage Instructions for the Sig
- The sensor requires a 1-hour start-up time after activation before glucose readings become available 2
- Patients scan the sensor with a reader device as needed to obtain real-time glucose values and trend arrows 3, 2
- The sensor measures glucose every minute and records measurements every 15 minutes 2
- Full 24-hour data can be captured if the sensor is scanned at least every 8 hours 3
Important Prescribing Considerations
- Unlike real-time CGM systems, the FreeStyle Libre 3 Plus does not provide automated alarms for high or low glucose values, though it does display trend arrows when scanned 3
- The device is water-resistant and can be worn during normal daily activities 2
- Contact dermatitis has been reported with CGM devices, sometimes linked to isobornyl acrylate, a skin sensitizer in the adhesive 2, 5
- Patients should be advised to rotate application sites to minimize skin reactions 5
Quantity to Prescribe
- For continuous monitoring, prescribe 2 sensors per month (each sensor lasts 15 days) 1
- Include one reader device if the patient does not already have one compatible with the FreeStyle Libre 3 Plus system
Clinical Accuracy Data
- The device demonstrates high accuracy with a mean absolute relative difference (MARD) of 8.2% in adults and 8.1% in pediatric participants ages 6-17 years 1
- In the hypoglycemic range, 97.1% of adult results and 98.0% of pediatric results were within ±15 mg/dL of laboratory comparator values 1
- Overall, 94.2% of adult readings and 94.0% of pediatric readings were within ±20 mg/dL or ±20% of comparator glucose values 1