How should insulin aspart (Novolog) and insulin glargine (Lantus) be used together in a basal‑bolus regimen?

Using Novolog and Lantus Together in a Basal-Bolus Regimen

Lantus (insulin glargine) should be administered once daily at the same time each day as your basal insulin, while Novolog (insulin aspart) should be injected before each meal as your prandial (bolus) insulin to cover postprandial glucose excursions. 1

Administration Timing and Technique

Lantus (Basal Insulin)

• Inject once daily at any time of day, but must be at the same time every day 2
• Can be administered in the morning or evening based on your schedule and glucose patterns 2
• Inject subcutaneously in the upper arm, abdomen, or thigh 2
• Rotate injection sites within the same body area to prevent lipodystrophy 2

Novolog (Prandial Insulin)

• Administer before each meal (typically 3 times daily) 1
• Can be dosed individually for each meal or adjusted based on the meal with the greatest postprandial glucose excursion 1
• Also inject subcutaneously, rotating sites 2

Critical Safety Rules

Never mix or dilute Lantus with any other insulin, including Novolog 2

• Mixing will cause Lantus to not work as intended and you may lose blood sugar control, which could be serious 2
• Each insulin must be drawn up and injected separately 2
• Use separate syringes or insulin pens for each insulin type 2

Injection Technique

• Always use a new needle for each injection 2
• After injecting, leave the needle in the skin for 10 seconds before removing 2
• Never share needles or insulin pens with others due to risk of blood-borne pathogen transmission 2
• Do not inject into the same site as your last injection 2

Dosing Considerations

Starting Prandial Insulin

When adding Novolog to existing Lantus therapy 1:

• Start with 4 units per meal OR 10% of your basal insulin dose
• Increase by 1-2 units or 10-15% as needed based on glucose readings
• If converting from NPH-based regimens, the total basal dose typically equals 80% of the previous NPH dose 1

Dose Adjustments

• For hypoglycemia: Determine the cause; if no clear reason exists, lower the corresponding insulin dose by 10-20% 1
• If A1C <8%, consider lowering basal dose by 4 units daily or 10% 1
• Test blood sugar frequently and adjust doses based on patterns 2

Factors Affecting Insulin Needs

Be aware that the following require dose adjustments 2:

• Illness: Test blood sugar more often and have a "sick day" plan
• Other medications: Many drugs affect insulin action; inform your healthcare provider of all medications
• Food intake: Eating less, skipping meals, or eating more than usual requires dose changes
• Alcohol consumption: Can affect how Lantus works and blood sugar levels
• Exercise: Physical activity changes insulin requirements
• Travel across time zones: Requires timing adjustments for injections

Storage Requirements

Unopened Lantus 2

• Store in refrigerator at 36°F–46°F (2°C–8°C)
• Good until expiration date
• Never freeze; discard if frozen

Opened (In-Use) Lantus 2

• Vials: Can be refrigerated or kept at room temperature (below 86°F/30°C) for up to 28 days
• SoloStar pens: Must be kept at room temperature only (do NOT refrigerate once opened) for up to 28 days
• Keep away from direct heat and light 2

Common Pitfalls to Avoid

• Accidental mix-ups: Always check the insulin label before each injection, as mix-ups between Lantus and rapid-acting insulins like Novolog have been reported 2
• Timing inconsistency: Taking Lantus at different times each day reduces its effectiveness 2
• Site rotation failure: Not rotating injection sites leads to lipodystrophy and unpredictable absorption 2
• Therapeutic inertia: Do not delay dose adjustments when glucose targets are not met 1

Visual Inspection

Before each injection 2:

• Lantus must be clear and colorless with no particles visible
• If cloudy or colored, return to pharmacy for replacement 2
• Do not use if the solution appears abnormal 2