Many forms of insulin are used to treat diabetes, with varying durations of action and peak activity times. Insulin glargine is a long-acting form of insulin. The dosage of insulin glargine varies from one person to another, depending on your weight, whether you have type 1 or type 2 diabetes, your response to the medication, and other diabetes drugs you are taking.
Starting Dose, Type 1 Diabetes
If you are a type 1 diabetic, the starting dose of insulin glargine is one-third of your total daily insulin requirement. The formula for calculating your daily insulin requirement is your weight, in pounds, divided by four. For example, if you weigh 132 pounds, your daily insulin requirement is 33 units. In this example, your starting dose of insulin glargine would be one-third of 33, or 11 units once per day.
Starting Dose, Type 2 Diabetes
If you have type 2 diabetes and are not already on insulin therapy, the recommended starting dose of insulin glargine is 10 units once daily. Alternatively, your doctor may calculate the starting dose based on your weight in kilograms. To calculate your weight in kilograms, divide your weight in pounds by 2.2. For example, if you weigh 132 pounds, your weight in kilograms is 60.
The daily dose of insulin glargine using weight-based dosing is your weight, in kilograms, times 0.2. Continuing with the example, the daily insulin glargine dose is 60 times 0.2, or 12 units.
Switching from NPH Insulin
Your doctor may switch you from intermediate-acting NPH insulin to long-acting insulin glargine. If you have been on NPH insulin once per day, your starting dose of insulin glargine will be the same as your NPH dose. For example, if you have been taking 11 units of NPH insulin once per day, you will replace the NPH with 11 units of insulin glargine.
If you have been taking NPH twice each day, your daily dose of insulin glargine will be 80 percent of your total daily NPH dose. For example, if you have been taking 5 units of NPH insulin twice each day, your daily NPH dose is 10 units. Your once-daily dose of insulin glargine will be 10 times 0.80, or 8 units.
Dosage Adjustments
Your doctor determines whether your insulin glargine dosage needs to be adjusted based on your home blood sugar monitoring and the hemoglobin A1c level in your bloodstream. Your hemoglobin A1c indicates how well your treatment has controlled your blood sugar levels over the previous two to three months. If your test results indicate that your blood sugar levels are too high, your doctor may adjust your dosage of insulin glargine or that of your other diabetes medications.
Warning
When taking any form of insulin, including insulin glargine, you must eat all your planned meals and snacks. Skipping meals or snacks when you are taking insulin may lead to a dangerous decrease in your blood sugar level, or hypoglycemia.
References
- Sanofi-Aventis: Lantus Prescribing Information
- Lantus.com: Dosing
- University of California San Francisco; Diabetes Education Online; Calculating Insulin Dose
- Endotext.org; The Management of Type 1 Diabetes; Irl B. Hirsch, M.D., Jay S. Skyler, M.D.; November 2009
- MedlinePlus: HbA1c
- Endotext.org; Insulin - Pharmacology, Types of Regimens, and Adjustments; Sinan Tanyolac, M.D., et al.; October 2010
