Insulin Management for Steroid‑Induced Hyperglycemia

Basal Insulin Dosing

For insulin‑naïve adults, the usual starting dose is 0.1–0.2 U/kg/day (≈10 U total) — this would correspond to roughly 11–23 U for an individual weighing about 110 kg【1】【2】.
In the setting of severe hyperglycemia (≥300 mg/dL) after high‑dose dexamethasone, a higher initial basal dose of 0.2–0.3 U/kg/day (≈22–34 U once daily) is recommended, with the upper range preferred when glucose is markedly elevated【1】.
Basal insulin should be increased by 2–4 U every 1–2 days until fasting glucose reaches 100–180 mg/dL【1】【2】.

Administer long‑acting insulin (e.g., insulin glargine) in the morning rather than at bedtime to align with the daytime hyperglycemic surge that peaks 4–6 hours after dexamethasone administration【2】【3】【4】.
Intermediate‑acting NPH insulin can be considered as an alternative because its duration more closely matches dexamethasone’s pharmacodynamics, although glargine provides steadier coverage as steroid effects wane【2】【3】【4】.

The conventional prandial ratio for most adults is 1 U per 10–15 g of carbohydrate【5】.
For patients with recent dexamethasone exposure and A1c around 8 %, an aggressive ratio of 1 U per 5–8 g carbohydrate is advised; start with 1:8 and tighten to 1:5 if post‑prandial glucose remains >180 mg/dL【1】【6】.

Use a high‑intensity correction factor of 1 U for every 20–30 mg/dL above the target glucose, rather than the typical 1 U per 50 mg/dL【1】【6】.
Deliver correction doses every 4–6 hours when the patient is not eating, or immediately before meals if eating【6】【7】.

Insulin requirements generally decline 48–72 hours after the dexamethasone dose【4】.
Once fasting glucose consistently falls below 100 mg/dL, reduce the basal dose by 10–20 % to avoid hypoglycemia【1】【6】.

Check capillary glucose at least four times daily (before each meal and at bedtime) to guide titration【1】.
Prescribe emergency glucagon for severe hypoglycemia, recognizing the risk of hypoglycemia that can appear after steroid discontinuation【1】【2】.

Sliding‑scale insulin alone is insufficient for steroid‑induced hyperglycemia and is linked to poorer outcomes, including diabetic ketoacidosis; a basal‑bolus regimen is preferred【5】.
Low hemoglobin may falsely lower A1c values, potentially under‑representing true glycemic exposure; persistent severe glucose readings confirm inadequate control despite any A1c discrepancy【1】.