Insulin Types and Administration

Insulin Classification and Action

The American Academy of Family Physicians recommends classifying insulins into four categories: rapid, short, intermediate, and prolonged, each with specific characteristics that determine their optimal clinical use for glucose control 1
Rapid-acting insulins have a fast onset of action (5 minutes), peak between 1-2 hours, and duration of 3-4 hours, primarily controlling postprandial glucose levels 1
The American Academy of Family Physicians suggests that short-acting insulins have an onset of action in 15 minutes, peak between 3-4 hours, and duration of 6-8 hours 1

The American Diabetes Association recommends using insulin concentrations with higher concentrations than standard U-100, such as U-500, for patients requiring high doses of insulin 2
Insulin U-500 has a delayed onset and longer duration, similar to an intermediate-acting insulin, and is indicated for patients needing more than 200 units of insulin daily 3

The American Diabetes Association suggests injecting insulin into the subcutaneous tissue of the arm, thighs, buttocks, and abdomen, with varying absorption rates depending on the site 4
Exercise increases the absorption rate at injection sites, likely due to increased blood flow, and rotation within the same area is recommended to reduce day-to-day variability in absorption 4

The American Diabetes Association recommends considering the effectiveness of insulin based on its proper use, patient selection, and dose adjustment according to changes in diet, activity, or weight 5
Long-acting insulin analogs have a lower absolute risk of hypoglycemia compared to NPH but are more expensive 5

The American Academy of Family Physicians suggests using options such as syringes, insulin pens, and insulin pumps for insulin administration, with varying costs and convenience 1
Insulin pens are more expensive than syringes but may be more convenient, while insulin pumps provide more physiological insulin replacement but are more difficult to use 1

The American Diabetes Association recommends the use of intermediate-acting insulin, such as NPH (Neutral Protamine Hagedorn) insulin, which has a less flat activity profile compared to long-acting analogs, with more pronounced peaks 6
Long-acting (basal) insulin analogs, such as insulin glargine (U-100, U-300), insulin detemir, and insulin degludec, have longer duration of action with flatter, more constant plasma concentrations and activity profiles than NPH insulin, and are associated with less hypoglycemia and weight gain compared to NPH insulin 6

The American Diabetes Association suggests that the total daily insulin requirement for type 1 diabetes is typically 0.4-1.0 units/kg/day, with 0.5 units/kg/day as a typical starting dose in metabolically stable patients, and that approximately 50% of daily insulin should be administered as basal and 50% as prandial 6
Basal insulin should be titrated to regulate overnight and fasting glucose, while prandial insulin timing varies based on formulation pharmacokinetics, premeal blood glucose level, and carbohydrate consumption 6

Newer formulations of long-acting analogs, such as U-300 glargine and degludec, may confer even lower hypoglycemia risk compared to U-100 glargine in type 1 diabetes 6