Examples
The different
types of insulin are categorized according to how fast
they start to work (onset) and how long they continue to work (duration). The
types now available include rapid-, short-, intermediate-, and long-acting
insulin.
Rapid-acting
|
| insulin aspart | NovoLog |
| insulin glulisine | Apidra |
| insulin lispro | Humalog |
Short-acting
|
| insulin regular | Humulin R, Novolin R, Humulin R U-500 |
Intermediate-acting
|
| insulin NPH | Humulin N, Novolin N |
Long-acting
|
| insulin detemir | Levemir |
| insulin glargine | Lantus |
Mixtures
|
| 70% NPH and 30%
regular | Humulin 70/30, Novolin 70/30 |
| 50%
lispro protamine and 50% lispro | Humalog Mix 50/50 |
| 75% lispro protamine and 25% lispro | Humalog Mix 75/25 |
| 70% aspart protamine and 30% aspart | NovoLog Mix 70/30 |
| 50% NPH and 50% regular | Humulin 50/50 |
Packaging
Injectable insulin is packaged in small
glass
vials (bottles) and cartridges that hold more than one
dose and are sealed with rubber lids. The cartridges are used in pen-shaped
devices called insulin pens.
How insulin is taken
Insulin usually is given as
an injection into the tissues under the skin (subcutaneous). It can also be
given through an
insulin pump, an
insulin pen, or jet injector, a device that sprays the
medicine into the skin. Some insulins can be given through a vein (only in a
hospital).
Research is ongoing to develop not only new forms of
insulin but also insulin that can be taken in other ways, such as by mouth.
How It Works
Insulin lets sugar (glucose) in the
blood enter cells, where it is used for energy. Without insulin, the blood
sugar level rises above what is safe for the body. If the cells don't get sugar to use for energy, they try to use other nutrients in the body. When this happens, acids can build up. Too much acid production (ketoacidosis) can be serious or even life-threatening.
Your body uses
insulin in different ways. Sometimes you need insulin to work quickly to reduce
blood sugar. Your body also needs insulin on a regular basis to keep your blood
sugar in a target range.
- Rapid-acting and short-acting insulins reduce
blood sugar levels quickly and then wear off.
- When you use
intermediate- or long-acting insulin with rapid- or short-acting insulins, the longer acting
insulin starts taking effect when the shorter acting insulin begins to wear
off. For example, the long-acting insulin glargine (Lantus) starts to work within 1 to 2
hours after it is given and continues to work at the same rate for about 24
hours. Lantus cannot be mixed in the same syringe with other types of
insulin.
- Usually people who take insulin use a combination of a
rapid- or short-acting and an intermediate- or long-acting insulin. This helps
keep blood sugar levels within a range that is safe for the body throughout the
day.
Why It Is Used
Insulin is used to treat:
- People who have
type 1 diabetes.
- People with
type 2 diabetes whose
pancreas produces little or no insulin or whose oral
medicines do not control their blood sugar. These people may take insulin
either by itself or along with oral medicine.
- People with type 2
diabetes whose blood sugar levels are high because of a severe illness or major
surgery. After blood sugar levels return to a target range, these people may be
able to stop taking insulin.
- Women with type 2 diabetes who are
pregnant or breast-feeding and who cannot keep their blood sugar levels in a
target range with diet and exercise. Only one oral
diabetes medicine (glyburide) has been studied for use during pregnancy. Until
further research is done, the American Diabetes Association recommends that
pregnant women and women who are breast-feeding not take oral diabetes
medicines.
How Well It Works
Insulin is effective in reducing
blood sugar levels by helping sugar (glucose) enter the cells to be used for
energy.
For people with type 1 diabetes
Results of the
10-year
Diabetes Control and Complications Trial (DCCT) and
the follow-up Epidemiology of Diabetes Interventions and Complications (EDIC)
study showed that people with type 1 diabetes who kept their blood sugar levels
in a target range had
fewer incidences of eye, kidney, and nerve damage from diabetes than people who
were on standard therapy. Tightly controlled therapy also lowered the risk of
heart attacks and deaths from heart disease.1
Studies have shown that insulin glargine (Lantus) and insulin determir (Levemir) work as well as NPH
insulin for controlling blood sugar in people who have type 1 diabetes. Lantus and Levemir
cause fewer low blood sugar episodes than NPH, especially at night.2
Side Effects
The major side effect of insulin can be
a dangerously low blood sugar level (severe hypoglycemia). A very low blood
sugar level can develop in 10 to 15 minutes with rapid-acting
insulins.
Insulin can contribute to weight gain, especially in
people with type 2 diabetes who already are overweight.
Other
possible side effects of long-term insulin use include the loss of fatty tissue
(lipodystrophy) where the insulin is injected and, in rare cases, allergic
reactions that include swelling, or edema.
See Drug Reference for
a full list of side effects. (Drug Reference is not available in all
systems.)
What To Think About
People with type 1 diabetes who
tightly control their blood sugar levels using either multiple daily injections
or the insulin pump have lower hemoglobin A1c levels and may reduce their risk
for small blood vessel complications (eye and kidney disease)
compared to people who take one or two injections every day.
The
insulin pump provides a way to give insulin with less
frequent injections and is as effective as multiple daily injections at keeping
blood sugar levels in a target range.
The long-acting insulin
glargine (Lantus) may help prevent some people from having frequent nighttime
low blood sugar levels. It may also help people who have had
difficulty keeping their blood sugar levels in their target range with
intermediate-acting insulin.
Giving short-acting insulin at the
evening meal and NPH at bedtime instead of giving them together at the evening
meal may reduce the risk of
nocturnal hypoglycemia and
hypoglycemia unawareness.
What can affect insulin
Some things that affect
how fast and how well an insulin dose works are:
- Where the dose is given. If you give insulin
into your abdomen (especially above and to the side of your belly button), the
medicine will get into your system more consistently from day to day. If the
medicine is given into a muscle or a small blood vessel instead of fatty
tissue, the medicine will get into your system faster.
- How much
insulin is given. Higher doses of insulin reduce the blood sugar level more
than lower doses.
- Whether you have exercised before or just after taking insulin.
If you have just exercised the muscles in the area where you give your insulin
injection, the medicine will get into your system faster.
- If you
apply heat to the area. The medicine will get into your system faster if you
take a hot bath or shower, put on a heat pack, or massage the area where you
have just given your insulin injection.
- If you do not have enough
fluid in your body (you are dehydrated), you will not have as much blood flow
to your skin, so insulin will not be absorbed as well as it would be
otherwise.
Things to do
- Label each insulin bottle when it is used
for the first time, and discard unused medicine after 30 days. A bottle of
insulin may lose its ability to work well (potency) after 30 days of
use.
- Store insulin properly so that its effectiveness is
protected.
- When you buy insulin, check the generic or brand names
to make sure you are buying the correct type. For example, if you have been
using Humulin R (insulin regular), make sure you buy Humulin R instead of
Humulin N (insulin NPH).
- Know when your prescribed types of insulin start working
(onset), when they work most (peak), and how long they work
(duration).
- Know how to give an insulin injection.
Diabetes: Giving Yourself an Insulin Shot- Diabetes in Children: Giving Insulin Shots to a Child
Precautions to take with long-acting insulin
The
long-acting insulin glargine (Lantus):
- Should be used only if it is clear,
colorless, and contains no particles.
- Should not be given using a
syringe that has been used to give another type of insulin.
- Should
not be mixed with any other type of insulin. People who cannot take multiple
injections may not be able to take this medicine.
- Should be clearly
labeled so it is not confused with short-acting insulins, which also are clear.
- Usually is injected as one dose at bedtime. But it can be taken in
the morning, and it can be split into morning and evening
doses.
- May cause more discomfort at the injection site than other
types of insulin, because it is acidic.
- Should not be used in an
insulin pump.
Children with type 2 diabetes
Insulin may be given
to a child as a single nighttime dose or as several smaller doses throughout the
day.
Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.
References
Citations
- Diabetes Control and Complications Trial/Epidemiology
of Diabetes Interventions and Complications Study Research Group (2005).
Intensive diabetes treatment and cardiovascular disease in patients with type 1
diabetes. New England Journal of Medicine, 353(25):
2643–2653.
- Bolli GB, et al. (2009). Comparison of a multiple daily insulin injection regimen (basal once-daily glargine plus mealtime lispro) and continuous subcutaneous insulin infusion (lispro) in type 1 diabetes. Diabetes Care, 32(7): 1170–1176.
Credits
| By | Healthwise Staff |
|---|
| Primary Medical Reviewer | John Pope, MD - Pediatrics |
|---|
| Specialist Medical Reviewer | David C.W. Lau, MD, PhD, FRCPC - Endocrinology |
|---|
| Last Revised | October 1, 2010 |
|---|
Diabetes Control and Complications Trial/Epidemiology
of Diabetes Interventions and Complications Study Research Group (2005).
Intensive diabetes treatment and cardiovascular disease in patients with type 1
diabetes. New England Journal of Medicine, 353(25):
2643–2653.
Bolli GB, et al. (2009). Comparison of a multiple daily insulin injection regimen (basal once-daily glargine plus mealtime lispro) and continuous subcutaneous insulin infusion (lispro) in type 1 diabetes. Diabetes Care, 32(7): 1170–1176.
