The patient’s post‑breakfast glucose is 301 mg/dL after taking metformin 500 mg; should a correction dose of regular insulin (Actrapid) be given now?

Immediate Correction Dose of Actrapid Is Appropriate

Yes, give a correction dose of Actrapid (regular insulin) now for a post-breakfast glucose of 301 mg/dL, using 4 units as the appropriate dose for this degree of hyperglycemia. 1

Correction Insulin Dosing Protocol

• For pre-meal or post-meal glucose >250 mg/dL, administer 2 units of rapid-acting or regular insulin 1
• For glucose >350 mg/dL, administer 4 units 1
• At 301 mg/dL, the appropriate correction dose is 2–4 units of Actrapid, with 4 units being more appropriate given the severity 1

Critical Context: Metformin Alone Is Insufficient

• A post-breakfast glucose of 301 mg/dL indicates complete inadequacy of the current regimen 1
• Metformin 500 mg is a suboptimal dose; the maximum effective dose is 2000–2550 mg daily 1
• This single elevated reading likely reflects a pattern of inadequate glycemic control requiring immediate regimen intensification, not just correction 1

Immediate Actions Required

1. Administer Correction Dose Now

• Give 4 units of Actrapid (regular insulin) immediately 1
• Regular insulin should be given 30–45 minutes before meals for optimal effect, but for correction of existing hyperglycemia, administer immediately 1
• Recheck glucose 2–4 hours after administration to assess response 2

2. Urgent Regimen Intensification Needed

• Do not rely solely on correction doses; scheduled basal insulin must be established 1
• For glucose levels consistently ≥300 mg/dL, the American Diabetes Association recommends immediate basal-bolus insulin therapy rather than oral agents alone 1, 2
• Start basal insulin at 10 units once daily (or 0.1–0.2 units/kg/day) in addition to increasing metformin 1

3. Optimize Metformin Dosing

• Increase metformin to at least 1000 mg twice daily (2000 mg total) unless contraindicated 1
• Metformin should be continued when adding insulin, as this combination reduces total insulin requirements and provides superior glycemic control 1, 3

Monitoring After Correction Dose

• Check glucose 1–2 hours after Actrapid administration 1
• If glucose remains >300 mg/dL after 2 hours, give an additional correction dose and investigate underlying causes 1
• Watch for hypoglycemia 2–4 hours post-dose when insulin action peaks 2

Common Pitfalls to Avoid

• Never use correction insulin as monotherapy; sliding-scale insulin alone is condemned by all major diabetes guidelines and achieves adequate control in only 38% of patients versus 68% with scheduled basal-bolus therapy 1
• Do not delay transition to scheduled insulin when glucose values are consistently >250 mg/dL 1
• Do not give rapid-acting or regular insulin at bedtime as a sole correction dose, as this markedly raises nocturnal hypoglycemia risk 1
• Do not assume metformin 500 mg is adequate; this dose is far below the therapeutic range for most patients 1

Expected Outcome

• With appropriate correction dosing, glucose should decrease by approximately 30–50 mg/dL per unit of insulin, though individual sensitivity varies 1
• The 4-unit dose should lower glucose by approximately 120–200 mg/dL over 2–4 hours 1
• However, this correction addresses only the immediate hyperglycemia; without regimen intensification, glucose will remain poorly controlled 1