Insulin is the hormone normally made in the pancreas that stimulates the flow of sugar
- glucose - from the blood into the cells of the body.
Glucose provides the cells with the energy they need to function.
There are two main groups of insulins used in the treatment of diabetes: human insulins
and analog insulins, made by recombinant DNA technology.
The concentration of most insulins available in the United States is 100 units per milliliter.
A milliliter is equal to a cubic centimeter.
All insulin syringes are graduated to match this insulin concentration.
There are four categories of insulins depending on how quickly they start to work in the body
after injection:
*Very rapid acting insulin *Regular, or Rapid acting insulins
*Intermediate acting insulins *Long acting insulin.
*In addition, some insulins are marketed mixed together in different proportions to provide
both rapid and long acting effects.
Certain insulins can also be mixed together in the same syringe immediately prior to injection.
A very rapid acting form of insulin called Lispro insulin is marketed under the trade
name of Humalog.
A second form of very rapid acting insulin is called Aspart and is marketed under the
trade name Novolog.
Humalog and Novolog are:
*clear liquids.
*They begin to work 10 minutes after injection, *peak at 1 hour after injection,
*and last 3-4 hours in the body.
*Most patients also need a longer-acting insulin to maintain good control of their blood sugar.
Humalog and Novolog can be mixed with NPH insulin.
*Humalog and Novolog are used as "bolus" insulins to be given 15 minutes before a meal.
Most patients also need a longer-acting insulin to maintain good control of their blood sugar.
Humalog and Novolog can be mixed with NPH insulin.
*Check your blood sugar level before giving Humalog or Novalog.
Your doctor or diabetes educator will instruct you in determining your insulin dose based
on your blood sugar reading and anticipated meals and exercise.
Always check the bottle before drawing up the insulin.
If the solution is cloudy, discard the bottle.
*If you are mixing Humalog or Novalog with a longer-acting insulin, always draw up the
Humalog or Novalog first to maintain the purity and clarity of the Humalog and Novalog solutions.
Another solution of insulin that acts rapidly is called "Regular" or "R" insulin.
This insulin does not act as quickly as Humalog or Novalog.
Regular insulin is:
*a clear, colorless liquid.
*It begins to work 30 minutes after injection, *peaks at 3-5 hours
*and lasts 6-10 hours in the body.
Regular insulin is:
*usually given 30 minutes before a meal.
*It can also be mixed with in the same syringe with longer acting NPH insulin or given separately
immediately after each other.
*Glargine cannot be mixed with it.
Regular insulin is:
*the most stable of all the different types of insulin,
*but unopened regular insulin is best refrigerated.
*Always check the bottle before drawing up the insulin.
*If the solution is cloudy, discard the bottle.
*If you are mixing Regular with a longer-acting insulin, always draw up the Regular insulin
first to maintain the purity and clarity of the Regular solution.
Examples of intermediate acting insulins are NPH.
Intermediate acting insulins are:
*cloudy suspensions of crystalline insulin.
*They need to be gently rotated between the hands before being used.
*They begin to work 1 hour after injection, *peak at 6-12 hours after injection
*and last 20-24 hours in the body.
The intermediate insulins are:
*often given before breakfast.
*They may also be given at bedtime, depending on your blood glucose reading.
*They can be mixed in the same syringe with Regular, Lispro and Aspart insulins.
Ultralente is a long-acting insulin.
Ultralente is:
*a cloudy suspension.
*It begins to work 2-8 hours after injection, *peaks at about 12 hours
*and lasts around 18-24 hours in the body.
Ultralente insulin is:
*often given before breakfast.
*It may also be given before dinner in the evenings or at bedtime, on your doctor's instruction.
*It can be mixed in the same syringe with regular insulin.
*When unopened, it is best stored in the refrigerator.
Another long-acting insulin is called Glargine insulin.
It is an insulin analog manufactured by recombinant DNA technology.
Unlike other long-acting insulins, Glargine insulin is:
*a clear solution of insulin.
*It begins to work around 1 hour after injection.
*There is no pronounced peak.
*Small amounts of Glargine insulin are released slowly to provide a relatively constant amount
of insulin in the body over 24 hours.
*Glargine insulin cannot be mixed with any other insulin.
*A change to Glargine from NPH insulins s hould be done under the close supervision
of your medical team.
There are three stable, premixed formulations of insulin.
*One contains 70% of NPH insulin and 30% of Regular insulin.
*Another formulation contains 50% of NPH and 30% of Regular insulin.
*The third contains 75% of NPH and 25% of Humalog.
These mixtures:
*begin to work around one half hour after injection,
*peak in 2-8 hours *and last up to 24 hours in the body.
*As these premixed insulins contain rapid or very rapid acting insulin, they should
be taken before meals as directed by your medical team.
*With your doctor's instructions, several combinations of two different kinds of insulin
can be mixed together in the same syringe and given as one injection.
*Once mixed, the combined injection must be given immediately or the effect of the regular
component of the injection will be diminished.
*The rapid-acting insulins, Lispro, Aspart and Regular, can be mixed with the longer
acting NPH insulin.
*Glargine cannot be mixed with any other insulin.