In an adult patient on basal insulin glargine 20 units daily who is receiving prednisone and has a random blood glucose of 15 mmol/L, should a rapid‑acting insulin (insulin aspart, Novorapid) be added as a correction dose rather than using a sliding‑scale alone?

Yes, Administer Novorapid Correction Dose Immediately

A blood glucose of 15 mmol/L (270 mg/dL) in a patient on prednisone requires immediate correction with rapid-acting insulin (Novorapid/insulin aspart) in addition to optimizing the basal insulin regimen. 1

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Immediate Correction Dose Protocol

• Administer 2 units of Novorapid immediately for a pre-meal glucose >250 mg/dL (13.9 mmol/L), or 4 units if glucose >350 mg/dL (19.4 mmol/L) 2
• For this patient with glucose of 270 mg/dL (15 mmol/L), give 2 units of Novorapid as a correction dose 2
• This correction dose should be given in addition to any scheduled prandial insulin, not as a replacement 1

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Why Sliding-Scale Alone Is Inadequate

• Sliding-scale insulin as monotherapy is explicitly condemned by all major diabetes guidelines and achieves adequate glycemic control in only 38% of patients versus 68% with scheduled basal-bolus regimens 3
• Sliding-scale acts reactively—treating hyperglycemia only after it occurs—leading to dangerous glucose fluctuations and poor control 3
• This patient's glucose of 270 mg/dL signals complete inadequacy of the current insulin regimen, not merely a need for correction dosing 4

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Addressing the Prednisone-Induced Hyperglycemia

The Glucocorticoid Effect

• Prednisone causes disproportionate daytime hyperglycemia with peak effects 4-6 hours after morning dosing, while patients frequently reach normal glucose levels overnight 1
• Glucocorticoids inhibit insulin secretion and increase insulin resistance, requiring substantially higher insulin doses—often in "extraordinary amounts"—beyond typical ranges 1, 5

Optimal Insulin Regimen for Steroid-Induced Hyperglycemia

• For patients on once-daily morning prednisone, prandial insulin dosing with intermediate-acting (NPH) insulin is the standard approach rather than relying solely on long-acting basal insulin like glargine 1
• Consider switching from glargine 20 units to NPH insulin given before breakfast to better match the daytime hyperglycemic pattern caused by prednisone 1, 6, 7
• Increase prandial and correction insulin by 40-60% or more in addition to basal insulin for patients on steroids 4

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Immediate Regimen Adjustments Required

Step 1: Give Correction Dose Now

• Administer 2 units of Novorapid immediately for the current glucose of 270 mg/dL 2

Step 2: Establish Scheduled Prandial Insulin

• Start with 4 units of Novorapid before each of the three largest meals (or 10% of basal dose = 2 units) 1, 4
• Titrate prandial doses by 1-2 units every 3 days based on 2-hour postprandial glucose readings 1, 4

Step 3: Consider Switching Basal Insulin Type

• Replace glargine with NPH insulin before breakfast to better match prednisone's daytime hyperglycemic effect 1, 6, 7
• If continuing glargine, increase the dose by 4 units every 3 days until fasting glucose reaches 80-130 mg/dL (4.4-7.2 mmol/L) 1, 4

Step 4: Aggressive Dose Escalation

• For patients on glucocorticoids, initial insulin doses of 0.5 units/kg/day are recommended, with frequent upward adjustments 6
• Do not hesitate to use "extraordinary amounts" of insulin as glucocorticoid doses increase 1

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Monitoring and Titration

• Check glucose before each meal and at bedtime to guide insulin adjustments 1, 3
• Adjust insulin doses every 3 days based on glucose patterns—do not wait longer 4
• Target fasting glucose 80-130 mg/dL (4.4-7.2 mmol/L) and postprandial glucose <180 mg/dL (10 mmol/L) 1, 4

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Critical Pitfalls to Avoid

• Do not rely solely on correction doses when glucose values are consistently >250 mg/dL; scheduled basal-bolus insulin must be established 4, 3
• Do not continue glargine-only regimens for prednisone-induced hyperglycemia, as glargine may under-treat daytime hyperglycemia and cause nocturnal hypoglycemia 6, 7
• Do not give rapid-acting insulin at bedtime as a sole correction dose, as this markedly raises nocturnal hypoglycemia risk 1, 2
• Do not underestimate insulin requirements in steroid-treated patients; doses often need to be increased by 40-60% or more 4

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Expected Outcomes

• With appropriate basal-bolus therapy and aggressive titration, 68% of patients achieve mean glucose <140 mg/dL versus only 38% with sliding-scale alone 3
• Adjustments based on anticipated changes in glucocorticoid dosing and point-of-care glucose results are critical to prevent both hyper- and hypoglycemia 1