What is the conversion from Mixtard (Novomix) to basal insulin?

From the Guidelines

When transitioning from Mixtard to basal insulin, I recommend switching to a long-acting basal insulin such as insulin glargine (Lantus, Toujeo), insulin detemir (Levemir), or insulin degludec (Tresiba) with a starting dose of approximately 80% of the total daily Mixtard dose, as this approach has been shown to reduce the risk of hypoglycemia and improve glucose control 1. The most recent and highest quality study, published in 2025, suggests that long-acting basal analogs can reduce the risk of level 2 hypoglycemia and nocturnal hypoglycemia compared with NPH insulin 1. Key considerations when making this transition include:

• Starting with a dose of approximately 80% of the total daily Mixtard dose, given once daily
• Adding mealtime bolus insulin, such as insulin aspart (NovoRapid), insulin lispro (Humalog), or insulin glulisine (Apidra), before meals, starting at approximately 4-6 units per meal
• Monitoring blood glucose closely during the transition, checking before meals and at bedtime
• Adjusting the basal insulin dose by 2-4 units every 3-4 days until fasting glucose reaches target (typically 80-130 mg/dL or 4.4-7.2 mmol/L) It is also important to be aware of the potential for overbasalization with insulin therapy, which can be indicated by clinical signals such as high bedtime-to-morning or preprandial-to-postprandial glucose differential, hypoglycemia, and high glucose variability 1. In terms of specific dosing, the 2025 study suggests that doses can be converted unit for unit and subsequently adjusted based on glucose monitoring, with an initial dose reduction of 10-20% recommended for individuals in very tight management or at high risk for hypoglycemia 1. Overall, the transition from Mixtard to basal insulin can provide more flexibility in dosing and often better glucose control, as basal-bolus regimens more closely mimic normal physiologic insulin secretion, with the basal insulin providing background insulin coverage and bolus insulin addressing mealtime needs 1.

From the Research

Switching from Mixtard to Basal Insulin

• The decision to switch from Mixtard to basal insulin should be based on individual patient needs and glycemic control goals 2.
• Basal insulin is usually initiated at a conservative dose of 10 units/day or 0.1-0.2 units/kg/day, and then titrated thereafter based on patient self-measured fasting plasma glucose 2.
• When switching between basal insulins, a unit-to-unit switching approach is usually recommended, but this may not be appropriate for all patients and types of insulin 3.
• Glycemic control and risk of hypoglycemia must be closely monitored during the switching process 3.

Types of Basal Insulins

• Insulin glargine and insulin detemir are long-acting basal insulin analogs with pharmacokinetic and pharmacodynamic advantages over neutral protamine Hagedorn (NPH) insulin 4.
• Insulin glargine has a slower onset of action than NPH insulin and a longer duration of action with no peak activity 5.
• Insulin detemir has a lower within-subject variability, lower risk of hypoglycemia, and a weight-sparing effect compared to insulin glargine 4.

Dosing and Titration

• The dose of basal insulin should be increased as required up to approximately 0.5-1.0 units/kg/day in some cases 2.
• A simple rule for titrating basal insulin is to gradually increase the initial dose by 1 unit per day (NPH, insulin detemir, and glargine 100 units/mL) or 2-4 units once or twice per week (NPH, insulin detemir, glargine 100 and 300 units/mL, and degludec) until fasting plasma glucose levels remain consistently within the target range 2.
• Overbasalization (continuing to escalate dose without a meaningful reduction in fasting plasma glucose) is not recommended, and re-evaluation of individual therapy may be necessary 2.