How should the insulin regimen be adjusted for a patient currently receiving Novolin 70/30 (70% NPH, 30% regular insulin) 24 units in the morning and 28 units at night?

Adjusting Novolin 70/30 Insulin Regimen

The specific adjustment you make depends entirely on whether the patient's A1C is at goal or above goal, and which blood glucose values are out of range. Without knowing the patient's current glycemic control, here's the algorithmic approach based on the 2025 ADA Standards of Care:

Decision Algorithm

If A1C is Above Goal:

Option 1: Add GLP-1 RA First (Preferred)

• Before intensifying insulin further, strongly consider adding a GLP-1 RA or dual GIP/GLP-1 RA to the current Novolin 70/30 regimen 1
• This approach reduces hypoglycemia risk and weight gain while improving glycemic control
• May use a fixed-ratio combination product if appropriate

Option 2: Convert to Basal-Bolus Regimen If GLP-1 RA is not appropriate or already on board:

• Switch from Novolin 70/30 to a basal-bolus plan:
  • Calculate total daily dose: 24 + 28 = 52 units
  • Basal insulin (NPH or long-acting analog): 80% of current total = ~42 units (can split as twice-daily NPH or once-daily long-acting)
  • Add rapid-acting insulin: 4 units with largest meal OR 10% of basal dose (~4 units) 1
  • Titrate each component separately based on blood glucose patterns

Option 3: Adjust Current 70/30 Doses If staying on premixed insulin:

• Increase by 1-2 units or 10-15% of current dose 1
• Adjust morning dose based on pre-dinner glucose
• Adjust evening dose based on fasting glucose
• Research suggests optimal morning:evening ratio is approximately 55:45 to 60:40 (higher morning dose) 2
  • Current ratio is 46:54 (24:28), which is evening-heavy
  • Consider redistributing to ~29 units AM and ~23 units PM to achieve 55:45 ratio

If A1C is <8% (<64 mmol/mol):

• Consider lowering basal component by 4 units/day or 10% of dose 1
• This prevents overbasalization

If Hypoglycemia is Occurring:

• Determine the cause; if no clear reason, lower the corresponding dose by 10-20% 1
• Morning hypoglycemia → reduce evening dose
• Pre-dinner hypoglycemia → reduce morning dose
• Consider switching to a basal analog if recurrent nocturnal hypoglycemia 1

Key Clinical Signals for Overbasalization

Watch for these indicators that the current regimen needs restructuring rather than simple dose increases 1:

• Elevated bedtime-to-morning glucose differential
• Elevated postprandial-to-preprandial glucose differential
• Hypoglycemia (aware or unaware)
• High glucose variability
• Fasting glucose at goal but A1C still elevated

Titration Principles

• Set individualized fasting plasma glucose goal (typically 80-130 mg/dL)
• Increase by 2 units every 3 days to reach goal without hypoglycemia 1
• Assess adequacy at every visit 1
• Do not delay intensification (avoid therapeutic inertia) 1

Common Pitfalls to Avoid

1. Continuing to escalate premixed insulin doses without meaningful glucose reduction (overbasalization) - instead, transition to basal-bolus or add GLP-1 RA 1
2. Not considering GLP-1 RA before further insulin intensification - this class reduces cardiovascular risk and avoids weight gain 1
3. Using evening-heavy dosing ratios - morning dose should typically be higher (55-60% of total daily premixed dose) 2
4. Abruptly discontinuing oral medications when intensifying insulin 3

Practical Considerations

• Novolin 70/30 cannot be mixed with other insulins 4
• Inject into abdomen for faster absorption 4
• Rotate injection sites within chosen area 4
• Must be resuspended properly (roll 10 times until uniformly cloudy) 4
• Prescribe glucagon for emergency hypoglycemia 1