II. Indications
-
Diabetes Mellitus with very high Insulin Resistance
- Indicated for those with very high Insulin requirements (>200 units per day)
III. Mechanism
- See Insulin
- Humulin R U-500 is a Regular Insulin that is at 5-fold higher concentration than typical Regular Insulin
- At this very high concentration, Humulin R U-500 has Pharmacokinetics that are more like Basal insulin
- Despite being Regular Insulin, U-500 acts more like NPH or Insulin 70/30
IV. Medications
-
Humulin R U-500 (500 units/ml, green)
- Caution: This is 5-fold higher than standard Regular Insulin (U-100, at 100 units/ml)
- High risk for dosing errors (very concentrated Insulin)
- Specific U-500 green capped syringes are available as of 2016 to reduce dosing errors
- U-500 vials have been discontinued in the U.S. in 2026, and are replaced by U-500 Pens
- Each 20 ml vial of U-500 contains 10,000 units and expires 40 days after opening
- Each carton of U-500 pens contains 3000 units (one third of a vial)
- Pens are preferred for less dosing errors over vials and syringes
- Use pen dosing window (not the number of clicks to determine dose)
- Each click of a U-500 pen adds 5 units of Insulin (contrast with 1 unit/click with U-100)
- Each KwikPen lasts expires after 28 days
V. Dosing
- See Insulin Dosing
- See Insulin Dosing in Type I Diabetes
- See Insulin Dosing in Type II Diabetes
- Divide dosing twice (60 and 40%) to three times (e.g. 40, 30 and 30%) daily
- Do not combine with other Insulins (i.e. stop basal and mealtime Bolus Insulins)
- Use in similar fashion to 70/30 Insulin
VI. Pharmacokinetics
- Activity is similar to Insulin 70/30
- Onset: 30 minutes
- Duration: >12 hours
- Far longer duration than other Bolus Insulins (more like NPH Basal insulin)
VII. References
- (2022) Presc Lett 29(3): 14