How should a patient initiated on a basal-bolus regimen with Lantus (insulin glargine) 12 units and Actrapid (human insulin) 4-4-4 on an outpatient (OPD) basis monitor and adjust their insulin doses?

Monitoring and Adjusting Insulin Doses on Basal-Bolus Regimen

Patients on Lantus 12 units and Actrapid 4-4-4 should monitor fasting blood glucose daily and adjust Lantus by 2-4 units every 3 days based on fasting values, while adjusting Actrapid doses based on 2-hour postprandial glucose readings, with the goal of achieving fasting glucose 80-130 mg/dL and postprandial glucose <180 mg/dL. 1

Daily Monitoring Requirements

Self-monitoring of blood glucose is essential during the titration phase and should include:

• Fasting blood glucose every morning to guide basal insulin (Lantus) adjustments 1
• Pre-meal glucose readings before each meal to determine Actrapid dosing 1
• 2-hour postprandial glucose after meals to assess adequacy of Actrapid doses 1
• Record all glucose values to identify patterns over 3-day periods 1

Basal Insulin (Lantus) Adjustment Protocol

Adjust Lantus dose every 3 days based on fasting glucose patterns:

• If fasting glucose 140-179 mg/dL: Increase Lantus by 2 units 1
• If fasting glucose ≥180 mg/dL: Increase Lantus by 4 units 1
• If fasting glucose <80 mg/dL on more than 2 occasions per week: Decrease Lantus by 2 units 1
• Target fasting glucose: 80-130 mg/dL 1

The current dose of 12 units may be insufficient depending on the patient's weight—for a 60 kg patient, this represents only 0.2 units/kg/day, which is at the lower end of typical requirements 1. For patients with type 2 diabetes requiring basal-bolus therapy, total daily insulin doses of 0.3-0.5 units/kg/day are often needed 2.

Prandial Insulin (Actrapid) Adjustment Protocol

Adjust Actrapid doses based on postprandial glucose readings:

• If 2-hour postprandial glucose consistently >180 mg/dL: Increase the corresponding meal's Actrapid dose by 1-2 units or 10-15% 1
• If postprandial glucose <70 mg/dL: Decrease that meal's Actrapid dose by 10-20% 1
• Target postprandial glucose: <180 mg/dL 1

The current 4-4-4 regimen provides equal coverage for all meals, but this should be individualized based on meal size and carbohydrate content 1. The largest meal may require more insulin 1.

Critical Threshold Monitoring

Watch for signs of "overbasalization" that indicate the need to adjust the regimen rather than continue escalating Lantus:

• Basal insulin dose exceeding 0.5 units/kg/day (for a 60 kg patient, this would be >30 units) 1
• Large bedtime-to-morning glucose differential (≥50 mg/dL drop overnight) 1
• Episodes of hypoglycemia, especially nocturnal 1
• High glucose variability throughout the day 1

If Lantus exceeds 0.5 units/kg/day without achieving targets, the issue is likely inadequate prandial coverage rather than insufficient basal insulin 1.

Hypoglycemia Management

If hypoglycemia occurs (glucose <70 mg/dL):

• Treat immediately with 15 grams of fast-acting carbohydrate 1
• Determine the timing: if before meals, reduce Lantus by 10-20%; if after meals, reduce the corresponding Actrapid dose by 10-20% 1, 2
• If no clear cause is identified, reduce the relevant insulin component by 10-20% 1

Medication Continuation

Continue metformin unless contraindicated when using insulin therapy, as the combination provides superior glycemic control with reduced insulin requirements and less weight gain 1. The dose should be at least 1000 mg twice daily (2000 mg total) for optimal effect 1.

Reassessment Schedule

Follow this timeline for dose adjustments and monitoring:

• Every 3 days during active titration: Adjust insulin doses based on glucose patterns 1
• Every 3-6 months once stable: Check HbA1c and reassess overall glycemic control 1
• At every clinical visit: Assess for signs of overbasalization and hypoglycemia patterns 1

Common Pitfalls to Avoid

Do not continue escalating Lantus beyond 0.5-1.0 units/kg/day without addressing postprandial hyperglycemia, as this leads to increased hypoglycemia risk without improved control 1. If fasting glucose is controlled but HbA1c remains elevated after 3-6 months, the problem is postprandial hyperglycemia requiring adjustment of Actrapid doses, not more Lantus 1.

Do not discontinue metformin when starting or intensifying insulin therapy unless contraindicated 1. The combination is superior to insulin alone 1.

Do not wait longer than 3 days between adjustments in stable patients, as this unnecessarily prolongs time to achieve glycemic targets 1.

Administration Guidelines

Lantus must be given once daily at the same time each day (typically bedtime) and should never be mixed with Actrapid or any other insulin 3. Actrapid should be administered 0-15 minutes before meals for optimal postprandial glucose control 1, 4. Rotate injection sites within the same region (abdomen, thigh, or deltoid) to prevent lipodystrophy 3.