What types of insulin are recommended for patients requiring insulin therapy?

Types of Insulin Recommended for Patients Requiring Insulin Therapy

For patients requiring insulin therapy, the recommended types include basal insulins (long-acting analogs like glargine, detemir, and degludec or intermediate-acting NPH), rapid-acting analogs (lispro, aspart, glulisine), short-acting regular insulin, and premixed insulin formulations, with selection based on glycemic patterns, cost considerations, and risk of hypoglycemia. 1

Basal Insulin Options

Basal insulin provides relatively uniform insulin coverage throughout the day and night, primarily controlling blood glucose by suppressing hepatic glucose production between meals and during sleep 2.

• Long-acting analogs:

  • Insulin glargine (Lantus): Once-daily dosing, typically at bedtime 3
  • Insulin detemir: May require once or twice daily dosing
  • Insulin degludec: Once-daily dosing with more flexible timing 1

• Intermediate-acting:

  • NPH insulin: May require twice-daily dosing, more affordable option but higher risk of nocturnal hypoglycemia 2

Long-acting analogs have a lower risk of nocturnal hypoglycemia compared to NPH insulin and provide a more stable glucose profile 1, 4. However, NPH insulin may be a more affordable option for some patients, especially given substantial price increases for newer insulins over the past decade 2.

Prandial (Mealtime) Insulin Options

• Rapid-acting analogs:

  • Insulin lispro, aspart, glulisine: Preferred for mealtime coverage due to quick onset of action 2, 1
  • Typically dosed just before meals for better postprandial glucose control 2

• Short-acting:

  • Regular human insulin: Less costly but has a less favorable pharmacokinetic profile for mealtime coverage 2

Premixed Insulin Formulations

Premixed insulin products contain both basal and bolus insulin components to target both fasting and postprandial glycemia 2:

• 70/30 NPH/regular insulin mix
• 70/30 aspart mix
• 75/25 or 50/50 lispro mix

These are options for patients who may benefit from simpler dosing but require a relatively fixed meal schedule and carbohydrate content per meal 2.

Concentrated Insulin Products

Several concentrated insulin preparations are available for patients requiring large insulin doses 2:

• U-500 regular insulin: 5 times as concentrated as U-100, indicated for patients requiring >200 units/day
• U-300 glargine and U-200 degludec: Longer duration of action than their U-100 formulations
• U-200 lispro: Allows for less volume of insulin to be injected

These concentrated insulins may improve adherence for patients requiring large doses but may be more expensive than U-100 insulins 2.

Inhaled Insulin

Inhaled insulin is available for prandial use with a more limited dosing range 2. Important caveats:

• Contraindicated in patients with chronic lung disease (asthma, COPD)
• Not recommended for smokers or those who recently stopped smoking
• Requires spirometry testing before and after initiation of therapy

Insulin Selection Algorithm

1. For initial insulin therapy in type 2 diabetes:

   • Start with basal insulin (10 units/day or 0.1-0.2 units/kg/day) 1
   • Continue metformin and consider continuing other oral agents 1

2. For type 1 diabetes:

   • Combination of basal and prandial insulin required
   • Starting dose typically ranges from 0.4 to 1.0 units/kg/day of total insulin 1

3. If basal insulin alone is insufficient:

   • Add prandial insulin (4 units per meal, 0.1 units/kg per meal, or 10% of basal dose) 2
   • Consider GLP-1 receptor agonist before adding prandial insulin 1

4. For patients needing simplified regimens:

   • Consider premixed insulin twice daily 2, 1

Important Considerations

• Hypoglycemia risk: Long-acting analogs have lower risk of nocturnal hypoglycemia compared to NPH insulin 4, 5

• Cost considerations: NPH insulin may be more affordable than newer insulin analogs 2

• Mixing insulins:

  • Insulin glargine should not be mixed with other forms of insulin due to its low pH 2, 1
  • NPH and rapid-acting insulin can be mixed and used immediately or stored for future use 2
  • Mixing of short-acting and lente insulins is not recommended except for patients already adequately controlled on such a mixture 2

• Administration: Rotate injection sites within the same region to reduce the risk of lipodystrophy 3

• Monitoring: Increase frequency of blood glucose monitoring during changes to insulin regimen 3

By selecting the appropriate insulin type based on individual patient needs, glycemic patterns, and risk factors, clinicians can optimize diabetes management while minimizing hypoglycemia risk and improving quality of life.