What is the typical starting dose for insulin therapy?

Typical Starting Dose for Insulin Therapy

For patients with type 2 diabetes initiating insulin therapy, start with 10 units of basal insulin once daily or 0.1-0.2 units/kg body weight, administered at the same time each day. 1, 2, 3, 4

Initial Dosing by Diabetes Type

Type 2 Diabetes (Insulin-Naive Patients)

• Standard starting dose: 10 units once daily OR 0.1-0.2 units/kg body weight 1, 2, 3, 4
• Administer basal insulin (such as insulin glargine, detemir, or degludec) at the same time each day 3, 4
• Continue metformin when initiating insulin therapy 3
• Consider adding one additional non-insulin agent if needed 1, 3

Type 1 Diabetes

• Total daily insulin requirement: 0.4-1.0 units/kg/day 1, 2
• Typical starting dose for metabolically stable patients: 0.5 units/kg/day 1, 2
• Split dosing: approximately 50% as basal insulin and 50% as prandial (mealtime) insulin 1, 2
• For basal insulin specifically: approximately one-third of total daily insulin requirements 4
• Higher doses required during puberty, pregnancy, and acute illness 1

When to Consider Higher Initial Doses

For patients with more severe hyperglycemia, consider higher starting doses: 2, 3

• HbA1c ≥9% or blood glucose ≥300-350 mg/dL: consider basal-bolus regimen from the start 2, 3
• HbA1c 10-12% with symptomatic or catabolic features: initiate combination basal and prandial insulin 2, 3
• Severe uncontrolled hyperglycemia: 0.4-0.6 units/kg/day may be appropriate 2

Dose Titration Protocol

Increase the basal insulin dose by 2-4 units (or 10-15%) once or twice weekly until fasting blood glucose reaches target (80-130 mg/dL): 1, 2, 3

Specific Titration Algorithm

• If fasting glucose ≥180 mg/dL: increase by 4 units every 3 days 2
• If fasting glucose 140-179 mg/dL: increase by 2 units every 3 days 2
• If fasting glucose at target but HbA1c remains elevated after 3-6 months: consider adding prandial insulin rather than continuing to escalate basal insulin 1, 2

Critical Pitfalls to Avoid

Overbasalization

When basal insulin exceeds 0.5 units/kg/day, strongly consider adding prandial insulin rather than continuing to escalate basal insulin alone: 1, 2

Clinical signals of overbasalization include: 2

• Basal insulin dose >0.5 units/kg/day
• High bedtime-to-morning glucose differential (≥50 mg/dL)
• Hypoglycemia episodes
• High glucose variability despite adequate fasting glucose control

Delayed Insulin Initiation

• Do not delay insulin therapy in patients failing to achieve glycemic goals on oral agents 2, 3
• Avoid using insulin as a threat or describing it as a sign of personal failure 3

Inadequate Patient Education

Provide comprehensive education on: 3

• Self-monitoring of blood glucose (essential during titration phase) 2
• Recognition, prevention, and treatment of hypoglycemia 3
• Proper injection technique and site rotation 1, 4
• The progressive nature of diabetes and role of insulin therapy 3

Adding Prandial Insulin (When Needed)

If basal insulin is optimized (fasting glucose at target) but HbA1c remains above goal after 3-6 months, add prandial insulin: 1, 2, 3

• Starting prandial dose: 4 units per meal OR 10% of basal insulin dose 1, 2, 3
• Begin with the largest meal or meal causing greatest postprandial excursion 1, 2
• Use rapid-acting insulin analogs (lispro, aspart, glulisine) for prandial coverage 1
• Consider decreasing basal insulin by the same amount as the starting prandial dose 1

Special Populations

Hospitalized Patients

• Insulin-naive or low-dose insulin: 0.3-0.5 units/kg total daily dose, with half as basal 2
• High-dose home insulin (≥0.6 units/kg/day): reduce total daily dose by 20% to prevent hypoglycemia 2
• High-risk patients (elderly >65 years, renal failure, poor oral intake): use lower doses of 0.1-0.25 units/kg/day 2

Patients on Enteral/Parenteral Feeding

• Basal insulin needs: 30-50% of total daily insulin requirement 2
• Reasonable starting point: 10 units of insulin glargine every 24 hours 2

Administration Guidelines

• Administer subcutaneously into abdomen, thigh, or deltoid 4
• Rotate injection sites within the same region to reduce lipodystrophy risk 4
• Do not dilute or mix insulin glargine with any other insulin or solution 2, 4
• Do not administer intravenously or via insulin pump 4
• Administer at the same time each day for consistency 2, 4