Is injecting rapid‑acting insulin (NovoRapid, insulin aspart) 15 units three times daily appropriate for an adult patient?

Atrapid 15 Units Three Times Daily: Regimen Assessment

Atrapid (regular human insulin) 15 units three times daily as monotherapy is inadequate and potentially dangerous for most patients requiring insulin therapy. This regimen lacks basal insulin coverage, leading to uncontrolled fasting hyperglycemia and dangerous glucose fluctuations between meals.

Critical Problems with This Regimen

Absence of Basal Insulin Coverage

• Regular insulin alone without intermediate or long-acting basal insulin has been shown to be ineffective as monotherapy in patients with established insulin requirements 1
• This "sliding-scale" or reactive approach treats hyperglycemia after it occurs rather than preventing it, leading to rapid glucose changes and exacerbating both hyper- and hypoglycemia 1
• Only 38% of patients achieve mean blood glucose <140 mg/dL with correction-dose insulin alone, versus 68% with proper basal-bolus therapy 1

Pharmacokinetic Limitations

• Regular insulin has a 6-8 hour duration of action, creating gaps in coverage between doses and increasing the risk of both postprandial hypoglycemia (4-6 hours after injection) and pre-meal hyperglycemia 2
• Without basal insulin, hepatic glucose production remains unsuppressed overnight and between meals, resulting in persistent fasting hyperglycemia 3

Recommended Insulin Regimen Structure

For Type 2 Diabetes

• Start with basal insulin at 10 units once daily or 0.1-0.2 units/kg body weight, administered at the same time each day 3, 4
• For severe hyperglycemia (HbA1c ≥9%, glucose ≥300-350 mg/dL), initiate basal-bolus therapy immediately with 0.3-0.5 units/kg/day total dose, split 50% basal and 50% prandial 1
• Continue metformin at maximum tolerated dose (up to 2000-2550 mg daily) unless contraindicated, as this combination reduces total insulin requirements by 20-30% 3, 4

For Type 1 Diabetes

• Basal-bolus therapy is mandatory from the outset, with approximately 0.5 units/kg/day total dose 3
• Split as 40-50% basal insulin (long-acting analog once daily) and 50-60% prandial insulin (rapid-acting analog before each meal) 3
• Never use correction-dose insulin alone in type 1 diabetes, as this can precipitate diabetic ketoacidosis 1

Proper Basal-Bolus Titration Protocol

Basal Insulin Adjustment

• Increase by 2 units every 3 days if fasting glucose is 140-179 mg/dL 3
• Increase by 4 units every 3 days if fasting glucose is ≥180 mg/dL 3
• Target fasting glucose 80-130 mg/dL 3
• Stop escalating basal insulin when dose exceeds 0.5 units/kg/day; instead add or intensify prandial coverage 1, 3

Prandial Insulin Coverage

• Start with 4 units of rapid-acting insulin before the largest meal, or use 10% of the basal dose 3
• Titrate by 1-2 units or 10-15% every 3 days based on 2-hour postprandial glucose readings 3
• Target postprandial glucose <180 mg/dL 3

Correction Insulin Protocol

• Add 2 units rapid-acting insulin for pre-meal glucose >250 mg/dL 3
• Add 4 units rapid-acting insulin for pre-meal glucose >350 mg/dL 3
• Correction doses are supplements to scheduled insulin, never replacements 1

Advantages of Rapid-Acting Analogs Over Regular Insulin

• Rapid-acting analogs (insulin aspart, lispro, glulisine) have a faster onset (0.25-0.5 hours) and shorter duration (3-5 hours) compared to regular insulin 2, 5
• They provide better postprandial glucose control with lower post-meal glucose levels (mean 0.6-1.2 mmol/L reduction) 6
• 12% reduction in hypoglycemia frequency, particularly late postprandial (4-6 hour) events, compared to regular insulin 6, 5
• Can be administered 0-15 minutes before meals versus 30-45 minutes for regular insulin, improving treatment satisfaction and flexibility 6, 5

Common Pitfalls to Avoid

• Never continue correction-dose insulin as monotherapy when blood glucose remains consistently elevated; this approach is condemned by all major diabetes guidelines 1, 3
• Do not delay insulin intensification in patients not achieving glycemic goals, as this prolongs hyperglycemia exposure and increases complication risk 3
• Avoid giving rapid-acting insulin at bedtime as a sole correction dose, as this markedly increases nocturnal hypoglycemia risk 3
• Do not discontinue metformin when starting insulin unless contraindicated, as this leads to higher insulin requirements and more weight gain 3

Expected Clinical Outcomes with Proper Basal-Bolus Therapy

• 68% of patients achieve mean glucose <140 mg/dL with scheduled basal-bolus regimens versus only 38% with correction-dose insulin alone 1, 3
• HbA1c reduction of 2-3% is achievable within 3-6 months with appropriate insulin intensification 3
• No increase in hypoglycemia incidence when basal-bolus regimens are properly implemented compared to inadequate correction-dose approaches 1, 3

The current regimen of Atrapid 15 units three times daily should be immediately restructured to include basal insulin coverage, with consideration of switching to rapid-acting analogs for improved postprandial control and reduced hypoglycemia risk.