What is the initial dose of insulin glargine (long-acting insulin) for an elderly male patient weighing 160 pounds?

Initial Insulin Glargine Dosing for Elderly Male Weighing 160 lbs

Start insulin glargine at 0.2 units/kg (approximately 14-15 units) once daily, administered in the morning to minimize hypoglycemia risk in this elderly patient. 1

Dosing Calculation

• Patient weight: 160 lbs = 72.7 kg 1
• Starting dose: 0.2 units/kg × 72.7 kg = 14.5 units once daily 1
• Alternative approach: Start with up to 10 units once daily if more conservative initiation is preferred 1

The FDA label for insulin glargine specifically recommends 0.2 units/kg or up to 10 units once daily as the starting dose for insulin-naive patients with type 2 diabetes 1. For this 160-lb (72.7 kg) patient, this translates to approximately 14-15 units.

Timing and Administration Considerations for Elderly Patients

Administer in the morning rather than at bedtime to reduce nocturnal hypoglycemia risk, which is particularly important in elderly patients 2. The American Diabetes Association guidelines for older adults specifically recommend changing basal insulin timing from bedtime to morning when simplifying insulin regimens 2.

• Inject subcutaneously into the abdominal area, thigh, or deltoid 1
• Rotate injection sites within the same region to reduce lipodystrophy risk 1
• Administer at the same time each day for consistency 1

Titration Strategy

Titrate dose based on fasting finger-stick glucose results over one week 2:

• Target fasting glucose: 90-150 mg/dL (5.0-8.3 mmol/L) 2
• If ≥50% of fasting values are above goal: Increase dose by 2 units 2
• If >2 fasting values/week are <80 mg/dL: Decrease dose by 2 units 2

This conservative titration approach (2-unit increments weekly) is specifically designed for older adults to minimize hypoglycemia risk 2.

Important Safety Considerations for Elderly Patients

Hypoglycemia Risk Reduction

Elderly patients are at higher risk for hypoglycemia and its complications (falls, fractures, cognitive impairment) 2. The starting dose of 0.2 units/kg is already conservative compared to younger patients 1.

• Consider starting even lower (0.1-0.15 units/kg = 7-11 units) if the patient has reduced oral intake, frailty, or multiple comorbidities 2
• Monitor for hypoglycemia more frequently during dose adjustments 1
• Ensure patient or caregiver can recognize and treat hypoglycemia 2

Individualized Glycemic Targets

The A1C target should be adjusted based on the patient's health status 2:

• Healthy elderly (few comorbidities, intact function): A1C <7.0-7.5% 2
• Complex/intermediate health: A1C <8.0% 2
• Very complex/poor health: A1C <8.5% 2

More relaxed targets reduce hypoglycemia risk while maintaining quality of life 2.

Monitoring Requirements

• Increase frequency of blood glucose monitoring during insulin initiation and dose adjustments 1
• Check fasting glucose daily during titration phase 2
• Assess for hypoglycemia symptoms, especially nocturnal 2
• Evaluate cognitive and functional status to ensure safe insulin administration 2

Common Pitfalls to Avoid

• Do not administer at bedtime initially in elderly patients due to increased nocturnal hypoglycemia risk 2
• Do not use aggressive titration (>2 units/week) in older adults 2
• Do not mix or dilute insulin glargine with other insulins 1
• Do not administer intravenously or via insulin pump 1
• Avoid injection into areas of lipodystrophy, as this can cause unpredictable absorption and hypoglycemia 1

Additional Considerations

If the patient has reduced oral intake, acute illness, or hospitalization, consider starting at an even lower dose (0.1-0.15 units/kg = 7-11 units) with primarily basal insulin coverage 2. The patient's renal function, hepatic function, and concomitant medications should be assessed, as these may affect insulin requirements and necessitate dose adjustments 1.