Ask the Expert on . . . Lantus Conversion

Karen Shapiro, PharmD, BCPS

Disclosures

June 16, 2005

Question

Would you please explain how to convert 70/30 insulin coverage to Lantus coverage? When our patients are admitted to the hospital, they are usually converted to Lantus with a sliding scale.

Response from Karen Shapiro, PharmD, BCPS

In clinical studies, when patients were transferred from intermediate once-daily dosing to Lantus , the initial dose was not changed. When patients were on a twice-daily regimen, such as 70/30, the initial dose was reduced by approximately 20% to avoid the risk of hypoglycemia. Following this, the Lantus dose is adjusted based on patient response.[1] However, in hospitalized patients blood glucose levels can be high, even in patients without diabetes. This is particularly true in patients who are critically ill vs those in general wards. It is important to tightly control blood glucose levels in order to reduce mortality in the critically ill patient. It may not be appropriate to reduce the Lantus dose on the basis of individual levels.[2]

Patient example:

Patient AB is using 70/30 insulin twice daily, given as 22 units in the morning and 12 units in the evening. This gives AB a total daily insulin dose of 34 units. 70/30 insulin is 70% NPH and 30% regular. Patient AB is using 23.8, or 24 units of NPH and 10 units of regular.

The regular insulin will be dosed in the hospital per sliding scale with either regular insulin or a rapid-acting insulin such as Lispro . To convert the NPH dose to Lantus , the dose can be reduced by approximately 20% to (approximately) 20 units, especially if the patient has been well controlled previously at this dose and is not experiencing higher-than-normal values.

Additional considerations:

  • Be careful that nutritional intake matches insulin coverage. If nutrition ceases (new NPO status, interruption of feedings, etc), the insulin dose must be adjusted downward. You cannot adjust a 24-hour insulin on a stat-basis.
     

  • When educating hospital staff regarding Lantus conversion, be sure to include a point on the need to avoid mix-ups between Lantus and other insulins. Lantus can be confused with Lente and Lispro , especially if orders are handwritten. Lantus was originally approved for nighttime dosing only but is administered in some patients in the morning or used as a twice-daily regimen.[3]
     

  • Lantus cannot be mixed with other insulins. This will change the duration of action of both insulins and could result in prolonged hypoglycemia.
     

  • Lantus cannot be given by intravenous (IV) administration.
     

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