Diabetes Treatment: Insulin Types

Regular Insulin

• For diabetes treatment, regular insulin is typically injected before meals to control postprandial hyperglycemia or infused subcutaneously via insulin pump for basal glycemic control.
• Subcutaneous injection of regular insulin results in slightly delayed absorption due to the formation of small aggregates at the injection site.
• Regular insulin onset of action is 30 to 60 minutes, peaks in 1 to 5 hours, and persists for up to 10 hours.
• Regular insulin onset is slower than rapid-acting insulins and faster than longer-acting insulins.
• Most insulin pump users prefer rapid-acting insulin analogs over regular insulin due to the delayed onset of regular insulin.

NPH Insulin

• NPH insulin (Humulin N, Novolin N) is an intermediate-acting insulin created by conjugating regular insulin with protamine, a large protein.
• Protamine reduces the solubility of NPH insulin, delaying absorption and extending its duration of action.
• The delayed onset of NPH insulin makes it unsuitable for mealtime administration to control postprandial hyperglycemia.
• NPH insulin is typically injected twice or thrice daily to provide glycemic control between meals and overnight.
• NPH insulin is the only long-acting insulin currently available for mixing with short-acting insulins.
• Allergic reactions may occur due to protamine's foreign protein nature.

Insulin Glargine (U-100)

• Insulin glargine (U-100) (Lantus, Basaglar) is a modified human insulin with a prolonged duration of action (up to 24 hours).
• U-100 insulin glargine is indicated for once-daily subcutaneous dosing in adults and children with type 1 diabetes and adults with type 2 diabetes.
• Some patients may require twice-daily administration to achieve the full 24 hours of basal coverage.
• Dosing can be administered at any time of day but should be consistent if possible.
• U-100 insulin glargine differs from natural human insulin by four amino acids, forming microprecipitates upon subcutaneous injection that slowly dissolve, releasing insulin glargine gradually.
• Unlike other long-acting insulins, insulin glargine achieves relatively steady blood levels, avoiding peak-and-trough fluctuations.

Insulin Detemir

• Insulin detemir (Levemir) is a human insulin analog with a slow onset and dose-dependent duration of action.
• Effects persist for approximately 12 hours at low doses (0.2 units/kg) and up to 20 to 24 hours at higher doses (0.4 units/kg).
• Insulin detemir is used for basal glycemic control due to its slow onset and prolonged duration.
• It is not administered before meals to control postprandial hyperglycemia.
• Compared to NPH insulin, insulin detemir has a slower onset and longer duration.

Insulin Glargine (U-300)

• U-300 insulin glargine (Toujeo) is similar to U-100 insulin glargine but three times concentrated, extending its duration of action beyond 24 hours.
• U-300 insulin glargine is indicated for once-daily subcutaneous dosing in both type 1 and type 2 diabetes.
• Individuals who do not achieve a full 24 hours of effect with U-100 insulin glargine may benefit from using U-300 insulin glargine due to its extended duration of action.

Insulin Degludec

• Insulin degludec (Tresiba) is the only human insulin analog with effects that persist for up to 42 hours.
• Insulin degludec is used to provide basal glycemic control due to its prolonged duration.
• Similar to insulin glargine, insulin degludec does not have a peak.

Insulin Lispro

• Insulin lispro (Humalog) is a rapid-acting analog of regular insulin, with effects starting within 15 to 30 minutes of subcutaneous injection and lasting for 3 to 6 hours.
• Insulin lispro acts faster than regular insulin but has a shorter duration.
• The rapid onset of insulin lispro allows for administration immediately before or even after eating, unlike regular insulin, which is typically administered 30 to 60 minutes before meals.
• Insulin lispro's structure is nearly identical to natural insulin, except for the positions of two switched amino acids.
• This structural difference leads to less aggregation of insulin lispro molecules compared to regular insulin, explaining its faster action.

Insulin Aspart

• Insulin aspart (NovoLog) is a human insulin analog with a rapid onset (10 to 20 minutes) and short duration (3 to 5 hours).
• Insulin aspart is very similar to insulin lispro.

Insulin Glulisine

• Insulin glulisine (Apidra) is a synthetic analog of natural human insulin with a rapid onset (10 to 15 minutes) and short duration (3 to 5 hours).
• The rapid onset necessitates administration close to mealtime.

Inhaled Human Insulin

• Inhaled regular human insulin has a faster onset and shorter duration compared to subcutaneously injected regular insulin.
• Inhaled human insulin (Afrezza) is a mealtime insulin product used in people with type 1 and type 2 diabetes.
• Afrezza is available in cartridges containing 4, 8, or 12 units each.

Regular Insulin Injection

• Regular insulin (Humulin R, Novolin R) is unmodified human insulin.
• The product has four approved routes: subcutaneous injection, subcutaneous infusion, and intramuscular injection (rarely used).

Rapid-Acting Insulin Analogs

• Insulin lispro (Humalog): Rapid-acting analog of regular insulin; onset within 15-30 minutes, lasts 3-6 hours.
• Insulin aspart (NovoLog): Rapid-acting analog, similar to lispro; onset 10-20 minutes, lasts 3-5 hours.
• Insulin glulisine (Apidra): Synthetic analog, rapid onset (10-15 minutes), short duration (3-5 hours).
• Inhaled human insulin (Afrezza): Mealtime insulin for Type 1 and Type 2 diabetes; acts faster and has shorter duration than injected regular insulin.

Short-Acting Insulin

• Regular insulin (Humulin R, Novolin R): Unmodified human insulin; onset 30-60 minutes, peaks 1-5 hours, lasts up to 10 hours.
• Absorption: Delayed due to small aggregates forming at the injection site.

Intermediate-Acting Insulin

• Neutral protamine Hagedorn (NPH) insulin (Humulin N, Novolin N): Regular insulin conjugated with protamine, delaying absorption and extending duration.
• Onset: Delayed, making it unsuitable for mealtime control.
• Administration: Injected twice or thrice daily for between-meal and nighttime control.

Long-Acting Insulins

• Insulin glargine (U-100) (Lantus, Basaglar): Modified human insulin, prolonged duration (up to 24 hours).
• Administration: Once-daily subQ dosing, some patients require twice-daily doses for full coverage.
• Mechanism: Forms microprecipitates that slowly dissolve, releasing insulin gradually.
• Insulin detemir (Levemir): Human insulin analog with slow onset and dose-dependent duration (12 to 24 hours).
• Use: Provides basal control, not for mealtime adjustments.

Ultralong-Acting Insulins

• Insulin glargine (U-300) (Toujeo): Three times concentrated U-100 glargine, extending duration beyond 24 hours.
• Insulin degludec (Tresiba): Human insulin analog with prolonged effect (up to 42 hours).
• No peak: Blood levels remain relatively stable, unlike other long-acting insulins.

Rapid Acting Insulin

• Insulin lispro (Humalog) is a rapid-acting analog of regular insulin, effective 15 to 30 minutes after injection with a duration of 3 to 6 hours.
• Insulin lispro acts faster than regular insulin, can be administered immediately before or after a meal.
• Insulin aspart (NovoLog) is another rapid-acting insulin analog, effective 10 to 20 minutes after injection with a duration of 3 to 5 hours.
• Insulin glulisine (Apidra) is a synthetic analog similar to Insulin Lispro and Aspart, effective 10 to 15 minutes after injection with a duration of 3 to 5 hours.
• Inhaled human insulin (Afrezza) is a mealtime insulin product for type 1 and type 2 diabetes, available in cartridges containing 4, 8, or 12 units.

Short Acting Insulin

• Regular insulin (Humulin R, Novolin R) is unmodified human insulin, onset is 30 to 60 minutes with a peak at 1 to 5 hours and lasting up to 10 hours.
• Regular insulin is typically administered 30 to 60 minutes before meals.

Intermediate Acting Insulin

• Neutral protamine Hagedorn (NPH) insulin (Humulin N, Novolin N) is a conjugation of regular insulin with protamine, delaying absorption and extending duration.
• NPH insulin is administered twice or three times daily to provide glycemic control between meals and during the night.

Long Acting Insulin

• Insulin glargine (U-100) (Lantus, Basaglar) is a modified human insulin lasting up to 24 hours, administered once daily for type 1 and 2 diabetes.
• Insulin detemir (Levemir) is a human insulin analog with a slow onset and dose-dependent duration, persisting for 12 hours at low doses and up to 20 to 24 hours at higher doses.

Ultralong Acting Insulin

• Insulin glargine (U-300) (Toujeo) is a concentrated version of U-100 insulin glargine with a duration exceeding 24 hours, administered once daily.
• Insulin degludec (Tresiba) is a human insulin analog with effects lasting up to 42 hours, providing basal glycemic control without a peak.