What is the proper administration and regimen for insulin (INJ) injections?

Proper Administration and Regimen for Insulin Injections

The proper administration of insulin requires subcutaneous injection into appropriate sites (abdomen, thigh, upper arm, or buttocks), with systematic site rotation within one area to prevent lipohypertrophy, and individualized dosing based on blood glucose monitoring, with most patients requiring multiple daily injections for optimal glycemic control. 1

Insulin Storage and Preparation

• Unopened insulin vials should be refrigerated (36-86°F, 2-30°C), while insulin in use may be kept at room temperature to limit local irritation 1
• Always inspect insulin before use for changes (clumping, frosting, precipitation, or changes in clarity/color) that may indicate loss of potency 1
• Rapid- and short-acting insulins and insulin glargine should appear clear, while intermediate-acting insulins should be uniformly cloudy 1
• Always have a spare bottle of each type of insulin used, and check expiration dates before use 1

Injection Technique

• Inject insulin into the subcutaneous tissue of the upper arm, anterior/lateral aspects of thigh, buttocks, or abdomen (avoiding a 2-inch radius around the navel) 1
• For standard needles, pinch a fold of skin, inject at 90° angle; thin individuals or children may need to inject at 45° angle to avoid intramuscular injection 1
• Keep the needle embedded within the skin for 5 seconds after complete delivery of insulin, especially when using insulin pens 1
• Rotate injection sites systematically within one area (e.g., within abdomen) rather than rotating between different areas to decrease variability in absorption 1
• The abdomen has the fastest absorption rate, followed by arms, thighs, and buttocks - consider this when selecting injection sites 1

Insulin Mixing Guidelines

• No other medication or diluent should be mixed with insulin unless approved by the prescribing physician 1
• Insulin glargine should not be mixed with other insulins due to its low pH 1
• Rapid-acting insulin can be mixed with NPH, lente, and ultralente insulins 1
• When mixing rapid-acting insulin with intermediate- or long-acting insulin, inject the mixture within 15 minutes before a meal 1
• Mixing of short-acting and lente insulins is not recommended except for patients already adequately controlled on such mixtures 1
• Phosphate-buffered insulins (e.g., NPH) should not be mixed with lente insulins 1

Dosing Regimens

• For type 1 diabetes and many type 2 diabetes patients, three or more injections per day are typically required to meet glycemic goals 1
• Basal insulin (long-acting) is typically started at 0.1-0.2 units/kg per day for type 2 diabetes patients 1
• When adding prandial insulin, start with 4 units per day or 10% of basal dose with the largest meal or meal with greatest postprandial glucose excursion 1
• Titrate prandial insulin by increasing dose by 1-2 units or 10-15% twice weekly based on blood glucose monitoring 1
• For hypoglycemia, determine the cause and if no clear reason is found, lower the corresponding dose by 10-20% 1

Self-Monitoring and Adjustments

• Self-monitoring of blood glucose (SMBG) is essential for all insulin-using patients to guide dosage adjustments 1
• During illness, insulin must be continued even if the patient is unable to eat or is vomiting, with more frequent monitoring 2
• Insulin requirements often increase during illness despite decreased food intake 2
• During travel through three or more time zones, special insulin administration advice is needed 1

Special Considerations

• Insulin pen devices may be beneficial for visually impaired patients or those who eat in restaurants frequently 1
• Prefilled syringes are stable for up to 30 days when refrigerated, and should be stored vertically with needle pointing upward 1
• All insulin users should carry medical identification (bracelet or wallet card) 1
• All insulin-requiring individuals should carry at least 15g of carbohydrate for hypoglycemic episodes 1
• Family members and close contacts should be instructed in glucagon use for type 1 diabetes patients 1

Disposal and Safety

• Never recap, bend, or break needles due to risk of needle-stick injury 1
• Dispose of insulin syringes, pens, needles, and lancets according to local regulations 1
• When community disposal programs are unavailable, place used sharps in a puncture-resistant container 1
• Needle reuse is not recommended, particularly for patients with poor hygiene, acute illness, open wounds, or decreased resistance to infection 1

Common Pitfalls to Avoid

• Intramuscular injection (faster absorption, may cause unexpected hypoglycemia) 1
• Injecting cold insulin (can cause local irritation) 1
• Inadequate site rotation (can lead to lipohypertrophy and variable absorption) 1
• Mixing incompatible insulins (can alter pharmacokinetics unpredictably) 1
• Stopping insulin during illness (can lead to diabetic ketoacidosis, especially in type 1 diabetes) 2
• Forgetting to adjust insulin during exercise or changes in routine 1