Converting from Basal-Bolus to Ryzodeg (Insulin Degludec/Aspart)
For a patient on 16 units basal insulin and 48 units total rapid-acting insulin daily (3×16 units), start Ryzodeg at 50-52 units once daily with the largest meal, representing approximately 80% of the total daily dose (TDD) of 64 units.
Understanding the Current Regimen
Your patient's current insulin regimen consists of:
- Total Daily Dose (TDD): 64 units (16 basal + 48 rapid-acting) 1
- This represents a basal-bolus regimen that requires 4 daily injections
Conversion Strategy to Ryzodeg
Initial Dose Calculation
Start with 80% of the current TDD when switching from basal-bolus to Ryzodeg, which equals approximately 50-52 units once daily 1, 2. This conservative approach reduces hypoglycemia risk during the transition, as Ryzodeg contains both ultra-long-acting insulin degludec (providing >42 hours of basal coverage) and rapid-acting insulin aspart (providing prandial coverage) 3.
- The 20% dose reduction accounts for the ultra-long duration of insulin degludec and reduced variability compared to conventional basal insulins 2, 3
- Ryzodeg should be administered with the largest, most carbohydrate-rich meal of the day 1
Timing and Administration
Administer Ryzodeg once daily with the main meal (typically dinner for most patients), as the insulin aspart component provides immediate prandial coverage while insulin degludec establishes basal coverage over 24+ hours 1, 2. The timing can be flexible day-to-day once steady state is achieved (after 2-3 days), though consistency is preferred initially 3.
Titration Protocol
Weekly Dose Adjustments
Titrate the Ryzodeg dose in 2-unit increments once weekly based on fasting plasma glucose (FPG) measurements 1:
- Target FPG: 80-130 mg/dL (individualized based on hypoglycemia risk) 1
- If FPG >130 mg/dL: increase by 2 units 1
- If FPG <80 mg/dL or hypoglycemia occurs: decrease by 2-4 units 1
Monitoring Requirements
Check blood glucose at minimum: fasting, pre-meals, and 2 hours post-largest meal during the first 2-4 weeks 1. This identifies patterns and guides whether once-daily dosing is sufficient or if intensification to twice-daily is needed.
When to Intensify to Twice-Daily Ryzodeg
Consider advancing to twice-daily Ryzodeg if:
- HbA1c remains >7% after 3 months on optimized once-daily dosing 1
- Significant postprandial hyperglycemia (>180 mg/dL) occurs at meals other than the one covered by Ryzodeg 1
- Patient has multiple carbohydrate-rich meals requiring prandial coverage 1
For twice-daily dosing: split the total dose as 60% with breakfast and 40% with dinner, or distribute based on meal carbohydrate content 1.
Medication Adjustments
Discontinue or Reduce
Sulfonylureas should typically be discontinued when initiating Ryzodeg to prevent hypoglycemia 4. DPP-4 inhibitors are also typically discontinued with intensive insulin regimens 4.
Continue
Metformin should be maintained throughout the transition 4. SGLT-2 inhibitors or GLP-1 receptor agonists can be continued but may require Ryzodeg dose reduction of 10-20% 1.
Critical Pitfalls to Avoid
- Do not use a 1:1 dose conversion from basal-bolus to Ryzodeg; the 80% rule prevents hypoglycemia from insulin degludec's ultra-long action 1, 2
- Do not administer Ryzodeg at bedtime unless that is the largest meal; the aspart component is designed for prandial coverage 1
- Do not expect immediate steady-state: insulin degludec reaches steady state after 2-3 days, so avoid aggressive titration in the first week 3
- Do not overlook the need for intensification: if postprandial glucose at non-covered meals remains elevated, the patient may need twice-daily Ryzodeg or additional rapid-acting insulin 1
Alternative Consideration
If the patient requires maximum flexibility or has highly variable meal patterns, consider maintaining a basal-bolus regimen rather than switching to Ryzodeg 4. However, Ryzodeg offers the advantage of reducing injection burden from 4 to 1-2 daily injections while maintaining glycemic control comparable to basal-bolus regimens 2, 3.