What is an example prescription for a patient with diabetes requiring a Continuous Glucose Monitor (CGM) and insulin therapy?

Example Prescription for a Patient with Diabetes Requiring CGM and Insulin Therapy

For patients with diabetes requiring glucose monitoring and insulin therapy, a real-time continuous glucose monitor (rtCGM) should be prescribed along with appropriate insulin therapy, as this combination significantly reduces hypoglycemia risk and improves glycemic control. 1

Patient Assessment for CGM Prescription

CGM is particularly indicated for:

• Type 1 diabetes patients
• Type 2 diabetes patients on intensive insulin therapy (≥3 daily injections or insulin pump)
• Patients with problematic hypoglycemia (unexplained, recurrent, asymptomatic, or nocturnal)
• Patients with significant glycemic variability
• Patients with HbA1c above target despite optimized therapy 1, 2

Sample Prescription Format

For CGM Device:

Rx: FreeStyle Libre 3 sensor
Apply one sensor every 14 days to back of upper arm
Scan as needed for glucose monitoring
Quantity: 2 sensors
Refills: 6

For Insulin Therapy (Type 1 Diabetes):

Rx: Insulin Glargine (Lantus) 100 units/mL
Inject [X] units subcutaneously once daily at same time each day
Dispense: 3 mL SoloStar prefilled pens #3
Refills: 3

Rx: Rapid-acting insulin (e.g., insulin lispro)
Inject [X] units subcutaneously before meals based on carbohydrate intake and correction factor
Dispense: 3 mL prefilled pens #3
Refills: 3

Dosing Guidelines

For Type 1 Diabetes:

• Basal insulin (glargine): Approximately one-third of total daily insulin requirements
• Bolus insulin: Remaining two-thirds divided before meals 3

For Type 2 Diabetes:

• Starting dose of basal insulin: 0.2 units/kg or up to 10 units once daily
• Adjust based on blood glucose monitoring results 3

Patient Education Requirements

1. Device Training:

   • Proper sensor application and replacement every 14 days
   • Scanning technique (for isCGM) or receiver use (for rtCGM)
   • Understanding alerts and alarms (if applicable)

2. Data Interpretation:

   • Review of time in range (target: 3.9-10.0 mmol/L [70-180 mg/dL])
   • Identifying patterns requiring insulin adjustment
   • Understanding glucose trend arrows

3. Insulin Administration:

   • Proper injection technique
   • Rotation of injection sites
   • Storage of insulin
   • Dose adjustment based on CGM data 1

Follow-up Plan

• Schedule follow-up within 2-4 weeks of initial prescription
• Review CGM data to adjust insulin regimen
• Assess for skin reactions or technical issues with CGM
• Evaluate time in range, hypoglycemia frequency, and overall glycemic control 2

Important Considerations

• rtCGM devices should be used as close to daily as possible for maximum benefit
• isCGM devices should be scanned at minimum once every 8 hours to avoid data gaps
• Some CGM systems may require calibration with fingerstick glucose readings
• Certain medications (e.g., high-dose vitamin C, salicylic acid) may interfere with sensor accuracy
• Patients should maintain access to traditional blood glucose monitoring for backup 1, 2

Clinical Pearls

• CGM significantly reduces hypoglycemia risk while improving overall glycemic control
• Factory-calibrated systems like Dexcom G6 have demonstrated high accuracy (93.9% within ±20% of reference values) 4
• Patient selection and education are crucial for successful CGM implementation
• Regular review of CGM data is essential for optimizing insulin therapy 2, 5

By following this prescription framework and providing comprehensive education, patients with diabetes can effectively use CGM technology and insulin therapy to improve their glycemic control and reduce complications.