What is the recommended insulin dosing regimen for a patient with severe hyperglycemia (A1C of 11.8)?

Insulin Dosing for Severe Hyperglycemia (A1C 11.8%)

For a patient with an A1C of 11.8%, immediate initiation of basal-bolus insulin therapy is required, starting with a total daily dose of 0.3-0.5 units/kg/day, divided as 50% basal insulin and 50% prandial insulin across three meals. 1, 2

Immediate Treatment Approach

Start basal-bolus insulin immediately rather than basal insulin alone, as A1C ≥10% with this degree of hyperglycemia warrants both basal and prandial coverage from the outset 1, 2. This is common practice for patients presenting with A1C ≥10% or blood glucose ≥300 mg/dL, especially if symptoms of hyperglycemia (polyuria, polydipsia) or catabolic features (weight loss, hypertriglyceridemia, ketosis) are present 1.

Specific Dosing Algorithm

Basal Insulin Component:

• Start with 10 units once daily OR 0.1-0.2 units/kg/day of long-acting insulin (glargine or detemir) 1, 2, 3
• For severe hyperglycemia at this A1C level, consider the higher end: 0.3-0.4 units/kg/day as part of total daily dose 2, 3
• Administer at the same time each day 3

Prandial Insulin Component:

• Start with 4 units of rapid-acting insulin before each of the three largest meals OR use 10% of the basal insulin dose 2, 3
• Alternatively, begin with one injection at the largest meal and add to other meals sequentially based on glucose patterns 2

Titration Protocol

Basal Insulin Adjustment:

• Increase by 4 units every 3 days if fasting glucose ≥180 mg/dL 2, 3
• Increase by 2 units every 3 days if fasting glucose 140-179 mg/dL 2, 3
• Target fasting plasma glucose: 80-130 mg/dL 2, 3

Prandial Insulin Adjustment:

• Increase by 1-2 units or 10-15% twice weekly based on 2-hour postprandial glucose readings 2, 3
• Target postprandial glucose: <180 mg/dL 4

Essential Concurrent Therapy

Continue metformin at maximum tolerated dose (up to 2000-2500 mg daily) unless contraindicated, as this combination provides superior glycemic control with reduced insulin requirements and less weight gain compared to insulin alone 1, 2, 3. Metformin should be maintained even when intensifying insulin therapy 1, 2.

Discontinue sulfonylureas when implementing basal-bolus insulin regimens, as the combination significantly increases hypoglycemia risk 1, 2.

Critical Threshold to Monitor

When basal insulin exceeds 0.5 units/kg/day, this signals "overbasalization" and indicates the need for prandial insulin intensification rather than further basal insulin escalation 2, 3. Clinical signs include:

• Basal dose >0.5 units/kg/day 2
• Bedtime-to-morning glucose differential ≥50 mg/dL 2
• Hypoglycemia episodes 2
• High glucose variability 2

Alternative Consideration for Select Patients

For newly diagnosed patients without catabolic features, non-insulin regimens combining metformin with GLP-1 receptor agonists or SGLT2 inhibitors can achieve A1C reductions of 2-3% from baseline levels >11% 5, 6. However, insulin remains the most effective agent when A1C is ≥9-10% and provides more rapid glycemic control 1, 5.

Monitoring Requirements

• Daily fasting blood glucose monitoring during titration phase 2, 3
• Pre-meal and 2-hour postprandial glucose checks to guide prandial insulin adjustments 2
• Reassess A1C every 3 months during intensive titration 2
• Assess for hypoglycemia at every visit; if it occurs without clear cause, reduce insulin dose by 10-20% immediately 2, 3

Common Pitfalls to Avoid

Do not delay insulin initiation by trying additional oral agents first at this A1C level, as prolonged severe hyperglycemia (months at A1C >9%) increases complication risk 2.

Do not rely on sliding scale insulin alone without scheduled basal-bolus therapy, as this approach is explicitly condemned by all major diabetes guidelines and shown to be ineffective 2, 3.

Do not discontinue metformin when starting insulin unless contraindicated, as this leads to higher insulin requirements and more weight gain 2, 3.

Patient Education Essentials

Provide comprehensive education on 2, 3:

• Insulin injection technique and site rotation
• Self-monitoring of blood glucose
• Recognition and treatment of hypoglycemia (treat with 15 grams fast-acting carbohydrate)
• "Sick day" management rules
• Insulin storage and handling

Expected Outcomes

With appropriate basal-bolus therapy at weight-based dosing, A1C reduction of 2-3% is achievable from current levels, with 68% of patients achieving mean blood glucose <140 mg/dL 2. As glucose toxicity resolves over weeks to months, simplifying the regimen may become possible 1.