How do I convert a patient from 60 units a day of U200 (UltraLente, insulin) to Tresiba (insulin degludec)?

Converting U-200 Insulin Degludec (Tresiba) 60 Units Daily

When converting from 60 units daily of U-200 insulin degludec to standard U-100 Tresiba, no dose conversion is necessary—continue 60 units daily using the U-100 formulation, as the U-200 formulation has identical pharmacokinetics to U-100 and differs only in concentration. 1

Key Conversion Principles

No Dose Adjustment Required

• The U-200 formulation of insulin degludec has pharmacokinetics similar to the U-100 counterpart, meaning the biological effect per unit is identical 1
• The FDA label confirms: "DO NOT perform dose conversion when using the TRESIBA U-100 or U-200 FlexTouch pens. The dose window shows the number of insulin units to be delivered and no conversion is needed" 2
• Simply prescribe 60 units of U-100 Tresiba once daily at the same time the patient was taking their U-200 dose 2

Practical Switching Steps

For adults:

• Continue 60 units once daily, but note that U-100 can be administered at any time of day (offering more flexibility than the U-200 formulation) 2
• The patient will inject a larger volume (0.6 mL vs 0.3 mL) but the same number of units 1

For pediatric patients (if applicable):

• Since the dose is 60 units (well above 5 units), either U-100 FlexTouch pen or vial can be used 2
• Must maintain consistent timing of daily injection in pediatric patients 2

Monitoring During Transition

Initial Monitoring Period

• Increase frequency of blood glucose monitoring during the switch, particularly for the first 3-4 days 2
• Check blood glucose at least 4 times daily during adjustment period to identify any unexpected glycemic patterns 3
• The ultra-long half-life of degludec (17-21 hours) means steady-state takes several days to achieve 4, 5

What to Watch For

• Monitor for nocturnal hypoglycemia, though degludec has lower risk compared to other basal insulins 6
• Assess fasting morning glucose levels and adjust dose by 3-4 day intervals if needed 2
• The recommended adjustment increment is typically 10-15% or 2-4 units per change 1

Common Pitfalls to Avoid

Critical dosing errors:

• Do NOT transfer insulin from the FlexTouch pen into a syringe for administration—this can lead to severe overdosing 2
• Do NOT dilute or mix Tresiba with any other insulin or solution 2
• Always verify insulin labels before administration to prevent wrong insulin/wrong concentration errors 2

Pen selection considerations:

• U-100 FlexTouch delivers 1-80 units in 1-unit increments 2
• U-200 FlexTouch delivers 2-160 units in 2-unit increments 2
• For 60 units daily, either pen works, but U-100 offers more precise dosing flexibility 2

Injection site management:

• Rotate injection sites within the same region (thigh, upper arm, or abdomen) to reduce lipodystrophy risk 2
• Do not inject into areas of existing lipodystrophy or localized cutaneous amyloidosis 2