Managing Supplemental Insulin Dosing at Home
Correcting a short-term problem with your blood glucose level
Even if you take insulin or oral diabetes medications regularly, your blood glucose levels may occasionally register above your target goal. It is very important to monitor your blood glucose levels closely and let your physician know when they are consistently high. If you are ill, under significant stress, or taking new medications that can elevate glucose (steroids such as prednisone for example), you need to increase the frequency of your glucose monitoring and if your glucoses are significantly elevated, check your ketone status. Elevated ketones may be a warning of diabetic ketoacidosis (DKA). It is important for you to discuss sick days with your health care team.
Is it food, illness or a new medication?
Higher than usual blood glucose levels could be due to too many carbohydrates in your diet, illness, stress or certain medications such steroids. If your blood glucose levels are high from a specific food, that food may be something to have less of next time. If your blood glucose levels are consistently elevated when you are not sick or taking a temporary medication, you will need to work with your physician to improve your long-term blood glucose control by increasing your oral medications or by adding or increasing insulin.
When blood glucose levels are elevated for reasons other than diet, such as a temporary illness or new medication, supplemental insulin may be needed for a short period of time.
You should inform your doctor if your blood glucose level rises by 100 milligrams per deciliter (mg/dL) or more from its normal range or if you are spilling ketones while you are sick or taking a new medication. For example, if your blood glucose is normally in the 120s and with a new temporary medication or illness, it is in the 220s, supplemental insulin may be needed for a short time.
Remember to drink plenty of low carbohydrate fluids when your glucoses are high!
A supplement, not a replacement
It's called supplemental insulin dosing because it is given in addition to your already prescribed diabetes medicines. Remember, a supplemental insulin-dosing program is not a replacement for your normal long-acting insulin or oral diabetes medications and is used only to correct a short-term problem. The good news is that with the help of your physician or diabetes educator you can easily manage a supplemental insulin-dosing program at home.
Two types of insulin
The two types of insulin used in supplemental dosing regimens are short acting and rapid acting insulins. Short acting insulin (also called regular insulin) begins to work in 30 to 60 minutes, peaks in 2-4 hours and may last in the body 6-10 hours. Rapid acting insulin—also called lispro (Humalog), aspart (Novolog) or glulisine (Apidra)—begins to take effect in 5-15 minutes, peaks between 1-2 hours and only lasts in the body about 4-6 hours. Rapid acting insulins work faster and stay in the body for a shorter period of time than regular insulin, making it ideal for short-term supplemental insulin dosing and less likely to drop your glucose levels too low when combined with your regular insulin or oral medication regimen.
In a supplemental insulin regimen, insulin should be administered after the blood glucose measurement is taken as the amount of supplemental insulin given will depend on the blood glucose level. Remember, the supplemental insulin coverage is given to respond to a blood glucose level that is already elevated. In order to prevent elevated glucose levels in the future, you must continue to take your regular diabetes medications.
Here is an example of a possible supplemental insulin regimen:
If your pre-meal reading is greater than 140 mg/dl, you may be instructed to take two units of lispro before eating, and add another unit for every 30 points above 140, as in the following table. (Please note that this is an example only. Always follow your physician's recommendations.)
140-169 mg/dL = 2 units
170-199 mg/dL = 3 units
200-229 mg/dL = 4 units
This may continue up to a limit set by your doctor or diabetes educator.
Based on your blood glucose levels and current medication regimen your doctor or diabetes educator will determine which type of insulin is right for you, how long you should take it and how you should adjust your dose based on your blood glucose level.
Things to remember about a supplemental insulin dosing:
- It corrects a short-term problem with your glucose level-usually due to an illness or to the use of temporary medications such as steroids.
- It's a supplement, not a replacement for your normal insulin or oral medication program.
- Your doctor or diabetes educator will determine the type and amount of insulin based on your range of blood glucose results.
- Know how long the insulin will last and its peak times and, as always, monitor for signs and symptoms of low blood glucose levels.
- If your blood sugar levels are persistently elevated be sure to contact your physician so the needed adjustments can be made in your standing diabetes medications.
