What dose of 7030 (NPH/Regular) insulin is equivalent to 8 units of Humalog (insulin lispro) and 28 units of Lantus (insulin glargine)?

Converting Humalog and Lantus to 70/30 Insulin

Start with approximately 36 units of 70/30 insulin divided into two doses: 24 units before breakfast and 12 units before dinner, representing the total daily insulin dose (TDD) of 36 units from the current regimen. 1, 2

Calculation Rationale

The patient's current total daily insulin dose is:

• 8 units Humalog (rapid-acting prandial) + 28 units Lantus (basal) = 36 units TDD

When converting to 70/30 premixed insulin, the American Diabetes Association recommends calculating the current TDD and distributing it as twice-daily dosing with a 2/3 morning and 1/3 evening split to minimize nocturnal hypoglycemia risk. 3, 4

Specific Dosing Conversion

• Morning dose (before breakfast): 24 units of 70/30 insulin 1, 2
• Evening dose (before dinner): 12 units of 70/30 insulin 1, 2
• Timing: Administer 30 minutes before breakfast and dinner 2

This 2/3 vs 1/3 distribution is critical because equal morning and evening doses significantly increase nocturnal hypoglycemia risk. 4

Initial Dose Adjustment Considerations

Consider reducing the initial TDD by 10-20% (to approximately 29-32 units total) if the patient has any history of hypoglycemia, is elderly (>65 years), has renal impairment, or has unpredictable oral intake. 1 This would translate to:

• Morning: 19-21 units
• Evening: 10-11 units

The 70/30 formulation contains 70% NPH (intermediate-acting) and 30% regular insulin (short-acting), which provides both basal coverage and prandial coverage in a single injection. 3 However, this fixed ratio requires relatively consistent meal timing and carbohydrate content. 3

Titration Protocol

Adjust doses every 2-3 days based on self-monitoring of blood glucose, targeting fasting glucose of 90-150 mg/dL: 1, 2

• If ≥50% of fasting glucose values exceed goal: increase the evening dose by 2 units 1, 2
• If pre-dinner glucose is elevated: increase the morning dose by 2 units 1
• If >2 fasting values per week are <80 mg/dL: decrease the evening dose by 2 units 1
• For any hypoglycemia without clear cause: reduce the corresponding dose by 10-20% 3

Critical Monitoring Requirements

Increase blood glucose monitoring frequency to at least 4 times daily (fasting, pre-lunch, pre-dinner, bedtime) during the first 1-2 weeks after conversion. 4 The patient is at higher risk for hypoglycemia during this transition period because:

• Lantus provides steady 24-hour basal coverage without peaks, while NPH component of 70/30 has a pronounced peak at 4-12 hours 5
• The regular insulin component peaks at 2-4 hours, creating overlapping insulin action 3

Common Pitfalls to Avoid

Do not use equal morning and evening doses - this substantially increases nocturnal hypoglycemia risk and is explicitly discouraged by guidelines. 4

Do not continue this regimen indefinitely if A1C remains above target - if glycemic goals are not achieved after appropriate titration, this represents therapeutic inertia. Consider transitioning to basal-bolus therapy or adding a GLP-1 receptor agonist rather than continuing to escalate 70/30 doses. 1, 2

Discontinue any sulfonylureas or DPP-4 inhibitors to reduce hypoglycemia risk and avoid unnecessarily complex regimens, but maintain metformin if the patient is taking it. 1

Counsel the patient that meal timing must be consistent - the fixed 70/30 ratio requires eating approximately 30 minutes after injection and maintaining relatively consistent carbohydrate content at meals. 3, 2 Skipping meals or significant delays in eating after injection substantially increases hypoglycemia risk.

When This Regimen May Not Be Appropriate

If the patient has unpredictable eating patterns, highly variable carbohydrate intake, or requires precise insulin dosing flexibility, 70/30 insulin is not the optimal choice. 1 In these cases, continuing separate basal and prandial insulins (even if switching to NPH and regular insulin due to availability) would provide better glycemic control and safety. 4

Human regular/NPH 70/30 products are available at significantly lower cost than analog premixed insulins at select pharmacies, making this a cost-effective option for many patients. 3, 1