For a patient weighing 156.2 lb (≈ 70.9 kg), what are the appropriate basal insulin (e.g., insulin glargine) and rapid‑acting insulin (e.g., insulin lispro) doses?

Insulin Dosing for 156.2 lb (70.9 kg) Patient

For a hospitalized patient weighing 70.9 kg, start basal insulin at 14–21 units daily (0.2–0.3 U/kg/day) if blood glucose is 201–300 mg/dL, or 21 units daily (0.3 U/kg/day total daily dose, split 50% basal/50% bolus) if blood glucose exceeds 300 mg/dL; for rapid-acting insulin, use correction doses before meals or every 6 hours based on blood glucose levels 1, 2.

Dosing Algorithm Based on Clinical Presentation

Basal Insulin (Insulin Glargine)

The dose depends entirely on the patient's glycemic severity and prior insulin exposure:

Mild Hyperglycemia (BG <200 mg/dL):

• If insulin-naive or on <2 oral agents: Start low-dose basal insulin at 7–14 units daily (0.1–0.2 U/kg/day) 1, 3
• Add correction doses with rapid-acting insulin only as needed

Moderate Hyperglycemia (BG 201–300 mg/dL):

• Start basal insulin at 14–21 units daily (0.2–0.3 U/kg/day) 1, 2
• This applies if the patient is on multiple oral agents or using <0.6 U/kg/day insulin at home
• Add correction doses with rapid-acting insulin before meals or every 6 hours

Severe Hyperglycemia (BG >300 mg/dL):

• Start basal-bolus regimen with total daily dose of 21 units (0.3 U/kg/day)
• Split as 50% basal (≈11 units glargine once daily) and 50% bolus (divided among meals) 1
• If already on home insulin >0.6 U/kg/day, reduce home total daily dose by 20% and split similarly

Rapid-Acting Insulin (Insulin Lispro)

Correction Dose Strategy:

• Use rapid-acting insulin before meals or every 6 hours for correction only in mild-moderate hyperglycemia 1
• Do NOT use sliding scale alone without basal insulin—this is explicitly discouraged 2

Prandial Bolus Strategy (for severe hyperglycemia):

• Divide the bolus portion (50% of total daily dose) among three meals
• For 21 units total daily dose: ≈3.5 units before each meal (10.5 units total bolus/day)
• Withhold prandial doses if patient has poor oral intake 1

Critical Considerations

Timing and Administration

• Administer basal insulin glargine once daily at the same time each day (can be any time, but consistency is key) 4
• Inject subcutaneously in thighs, upper arms, or abdomen—rotate sites to prevent lipodystrophy 4
• Never mix glargine with other insulins 4

Dose Adjustments

• Titrate basal insulin to achieve fasting plasma glucose 90–130 mg/dL (5.0–7.2 mmol/L) 1, 5
• When fasting glucose targets cannot be achieved with reasonable basal doses, add prandial rapid-acting insulin 5
• Start with one prandial bolus before the meal causing highest post-meal glucose, then add others as needed 5

Safety Monitoring

• Reduce doses in renal insufficiency—kidney failure increases hypoglycemia risk due to decreased insulin clearance 2
• Implement hypoglycemia protocol when blood glucose <70 mg/dL 2
• Monitor for nocturnal hypoglycemia, though glargine has lower risk than NPH insulin 3, 6

Common Pitfalls to Avoid

1. Do not use correction insulin alone without basal coverage—this "sliding scale" approach is ineffective and dangerous 2
2. Do not use glargine in insulin pumps or IV—subcutaneous injection only 4
3. Do not mix glargine with any other insulin in the same syringe 4
4. Do not forget to reduce doses by 20% if converting from home insulin regimen to avoid hypoglycemia 1
5. Always use new needles—reuse increases infection risk and dosing errors 4

The 2024 ADA guidelines 2 and 2021 Lancet consensus 1 both emphasize that basal-bolus regimens with insulin analogs are preferred over sliding scale approaches for hospitalized patients, with dosing individualized to glycemic severity rather than using a one-size-fits-all approach.