What is the typical regimen for using long-acting (e.g. glargine (Lantus)) and short-acting (e.g. aspart (Novolog)) insulin in patients requiring insulin therapy?

Typical Regimen for Long-Acting and Short-Acting Insulin

In patients requiring insulin therapy, the standard approach is to initiate basal insulin (glargine) once daily at the same time each day, and add prandial short-acting insulin (aspart) before meals only if basal insulin alone fails to achieve glycemic targets. 1

Initial Insulin Strategy

Starting with Basal Insulin Alone

• Begin with long-acting basal insulin (glargine) as monotherapy unless the patient is markedly hyperglycemic or symptomatic 1
• Basal insulin provides uniform coverage throughout 24 hours to suppress hepatic glucose production between meals and overnight 1
• For Type 1 diabetes: Start with approximately one-third of total daily insulin requirements as basal insulin 2
• For Type 2 diabetes: Start with 0.2 units/kg or up to 10 units once daily 2
• Administer glargine once daily at any time, but must be at the same time every day 2

When to Add Prandial Insulin

• Add short-acting insulin (aspart) only when basal insulin alone is insufficient due to progressive loss of insulin secretory capacity 1
• This typically manifests as inadequate postprandial glucose control despite optimized basal insulin 1
• In Type 1 diabetes, prandial insulin is required from the outset concomitantly with basal insulin 2

Administration Technique

Timing Specifications

• Glargine (long-acting): Once daily at the same time each day 2
• Aspart (short-acting): Immediately before meals 3, 1
• When mixing rapid-acting with intermediate/long-acting insulin, inject within 15 minutes before a meal 4

Injection Site Rotation

• Rotate injection sites within the same anatomical region (abdomen, thigh, or deltoid), not between different regions 4, 2
• The abdomen provides fastest absorption, followed by arms, thighs, and buttocks 4
• Avoid injecting into areas of lipodystrophy or localized cutaneous amyloidosis 2

Critical Mixing Restrictions

Glargine cannot be mixed with any other insulin or solution due to its low pH diluent 1, 5, 2

• This requires separate injections when using both basal and prandial insulin 1
• No other medication or diluent should be mixed with any insulin product unless specifically approved by the prescribing physician 6
• Aspart can be mixed with NPH insulin if needed, but this is rarely done in modern practice 1

Storage Requirements

Unopened Insulin

• Refrigerate at 36-86°F (2-30°C) until expiration date 4, 2, 3
• Avoid extreme temperatures and excess agitation to prevent loss of potency 4

In-Use Insulin

• Glargine vials: 28 days at room temperature or refrigerated 2
• Glargine SoloStar pens: 28 days at room temperature (do not refrigerate once opened) 2
• Aspart vials: 28 days at room temperature or refrigerated 3
• Aspart SoloStar pens: 28 days at room temperature (do not refrigerate once opened) 3
• Insulin in use may be kept at room temperature to reduce local irritation from cold insulin 4

Monitoring and Adjustment

• Increase frequency of blood glucose monitoring during any insulin regimen changes 2
• Dosage adjustments should only be made under medical supervision with appropriate glucose monitoring 2
• Visual inspection before each use: glargine and aspart should be clear and colorless with no visible particles 2, 3

Common Pitfalls to Avoid

• Never share insulin pens, syringes, or needles between patients even if the needle is changed, due to blood-borne pathogen transmission risk 2, 3
• Do not administer glargine intravenously or via insulin pump 2
• Do not attempt to mix glargine with other insulins in the same syringe 1, 2
• When switching from twice-daily NPH to once-daily glargine, start with 80% of total NPH dose to reduce hypoglycemia risk 2
• Repeated injections into areas of lipodystrophy can cause hyperglycemia; sudden change to unaffected area can cause hypoglycemia 2