Should I maintain or adjust my prandial fixed doses of Actrapid (human insulin) on day 3, after increasing my basal dose of glargine (insulin glargine) on day 2, in a basal-bolus regimen for managing elevated pre-breakfast glucose levels?

Maintain Your Original Fixed Prandial Doses on Day 3

On day 3, keep your prandial Actrapid doses at the same fixed amounts as day 1 (8-8-6 units), continuing to add correction doses as needed based on pre-meal glucose levels. The basal glargine adjustment you made on night of day 2 addresses fasting hyperglycemia independently and does not require proportional increases in your prandial insulin 1, 2.

Why Basal and Prandial Insulin Are Adjusted Independently

Basal and prandial insulin serve fundamentally different physiological roles and are titrated based on different glucose patterns:

• Basal insulin (glargine) controls fasting and between-meal glucose by suppressing hepatic glucose production overnight and throughout the day 1, 2
• Prandial insulin (Actrapid) addresses postprandial glucose excursions after specific meals 1, 3
• The elevated pre-breakfast glucose on day 2 reflects inadequate basal coverage overnight, not insufficient dinner insulin from the previous evening 2

The Correct Titration Approach

Your basal insulin should be titrated every 3 days based on fasting glucose patterns, increasing by 2-4 units until fasting glucose reaches 80-130 mg/dL 1, 2. The adjustment you made on night of day 2 was appropriate for addressing the elevated morning glucose.

Your prandial insulin doses should be adjusted independently based on 2-hour postprandial glucose readings after each specific meal, increasing by 1-2 units every 3 days if postprandial glucose consistently exceeds 180 mg/dL 1, 2, 3. Since you're only on day 3, you haven't accumulated enough data to determine if your fixed prandial doses need adjustment.

The 50:50 Basal-Bolus Ratio Is Not a Daily Recalculation

The 50:50 ratio between basal and prandial insulin is a general starting framework, not a rigid requirement that must be maintained with every dose adjustment 2. This ratio applies to the initial calculation of total daily dose when starting a basal-bolus regimen, typically using 0.5 units/kg/day as total daily insulin for type 1 diabetes 2.

• Once therapy is initiated, each component is titrated independently based on its specific glucose target 2
• Basal insulin is adjusted based on fasting glucose patterns over several days 2
• Prandial insulin is adjusted based on postprandial glucose after individual meals 1, 2
• You do not recalculate and rebalance the 50:50 ratio daily or with each basal adjustment 2

Critical Monitoring Points for Day 3 and Beyond

Continue using correction doses in addition to your fixed prandial doses until you have sufficient data (typically 3 days of consistent patterns) to determine if the fixed prandial doses themselves need adjustment 1, 2.

Monitor these specific patterns:

• Fasting glucose each morning to assess basal insulin adequacy 1, 2
• Pre-meal glucose to calculate correction doses 2
• 2-hour postprandial glucose after each meal to assess whether fixed prandial doses need adjustment 1, 3

When to Adjust Your Fixed Prandial Doses

Increase your fixed prandial Actrapid doses by 1-2 units only when you observe consistent patterns over 3 days 1, 2:

• If 2-hour postprandial glucose consistently exceeds 180 mg/dL after a specific meal, increase that meal's fixed prandial dose 1, 3
• If you're consistently requiring correction doses of the same magnitude before a particular meal, consider incorporating that amount into the fixed dose 2

Common Pitfall to Avoid

Do not assume that increasing basal insulin requires proportional increases in prandial insulin. This misconception leads to overinsulinization and increased hypoglycemia risk 1, 2. The two components address different aspects of glucose control and must be titrated based on their respective glucose targets, not maintained in a fixed mathematical relationship throughout therapy.