Recommended Dosing and Administration Method for 70/30 Insulin
Premixed insulin 70/30 (Novolin 70/30, NPH/Regular) should be administered twice daily, with approximately two-thirds of the total daily dose given before breakfast and one-third before dinner, with typical starting doses of 0.3-0.5 units/kg/day for insulin-naive patients. 1
Dosing Recommendations
- For insulin-naive patients or those on low insulin doses, start with a total daily dose of 0.3-0.5 units/kg/day, with lower doses for patients at higher risk of hypoglycemia (elderly, renal impairment, poor oral intake) 2
- Distribute the total daily dose as approximately 2/3 before breakfast and 1/3 before dinner 1
- For patients transitioning from other insulin regimens, maintain the same total daily dose initially but adjust the distribution to the 2/3 morning and 1/3 evening pattern 1
- For patients already on higher insulin doses (≥0.6 units/kg/day), consider a 20% reduction in total daily dose to prevent hypoglycemia 2
Administration Method
- Administer subcutaneously 30 minutes before meals 3, 4
- Morning dose should be given before breakfast and evening dose before dinner 1
- Consistent meal timing is particularly important with premixed insulin regimens to avoid hypoglycemia 1
- Premixed insulin should be administered using either vials with insulin syringes or prefilled pens 2
Monitoring and Adjustment
- Monitor blood glucose levels frequently during initiation and dose adjustments 1
- Target both fasting and postprandial glucose levels 1
- Adjust doses based on patterns in blood glucose readings:
- Consider adding a third dose before lunch if twice-daily dosing fails to achieve glycemic targets 5
Clinical Considerations
Advantages
- Simpler regimen compared to basal-bolus therapy (fewer daily injections) 1
- May provide better glycemic control than sliding scale insulin alone 6
- Cost-effective option compared to multiple daily injection regimens 7
Limitations
- Associated with higher risk of hypoglycemia compared to basal-bolus regimens in hospitalized patients 2
- Less flexible than basal-bolus regimens for patients with variable meal timing or content 2
- Not recommended for hospitalized patients due to unacceptably high rates of iatrogenic hypoglycemia 2
Common Pitfalls to Avoid
- Avoid using the same dose for both morning and evening injections; the morning dose should typically be higher 1
- Never convert on a 1:1 basis without adjusting the distribution of morning and evening doses when switching from other insulin regimens 1
- Don't neglect monitoring during initiation or transition periods, as this is when hypoglycemia risk is highest 1
- Avoid using premixed insulin in hospitalized patients where basal-bolus regimens show better outcomes 2
Special Populations
- For patients receiving enteral nutrition, some guidelines suggest giving 70/30 mixed insulin with half at the start of the feed and the rest halfway through the feed, though data remain scarce 2
- For patients with type 1 diabetes, premixed insulin alone is not appropriate and should not be used as monotherapy 2