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Insulin

Written by Carmen Fookes, BPharm on March 14, 2018.

What is Insulin?

Insulin is a hormone that is produced naturally in our bodies. Its main role is to allow cells throughout the body to uptake glucose (sugar) and convert it into a form that can be used by these cells for energy. Without insulin, we cannot survive, and death from diabetes was a common occurrence until insulin was discovered in the early 1900s by Frederick Banting and Charles Best.

Naturally occurring human insulin is made by beta cells within the pancreas. When people without diabetes eat food, these beta cells sense sugar or other carbohydrates in the blood and release just the right amount of insulin necessary to maintain normal blood sugar levels.

What is insulin used for?

Insulin is used in the treatment of people with type 1 diabetes who produce little or no insulin. It may also be used in the treatment of type 2 diabetes if insulin levels remain low despite the use of other types of medications, although most people with type 2 diabetes do not require insulin in the early stages of the disease.

Insulin may also be given to pregnant women who develop a type of diabetes during pregnancy called gestational diabetes.

What are the differences between insulins?

Insulin is available as synthetic human insulin (made in a laboratory but resembles naturally occurring human insulin) and insulin analogues (human insulin that has been genetically modified). Insulin analogues are better than standard human insulin at mimicking natural insulin release.  They have a more predictable duration of action and more reliable absorption.

Insulins are typically classified as fast-acting (includes rapid-acting and short-acting insulins), intermediate-acting, and long-acting insulins.

Common Insulins available in the U.S.

Rapid-acting insulin

Short-acting insulin

Intermediate-acting insulin

Long-acting insulin

Ultra long-acting insulin

How is insulin administered?

Insulin is most commonly administered subcutaneously (under the skin) and there are three main delivery methods:

  • Insulin Pens: these hold a replaceable cartridge of insulin and use a replaceable needle to puncture the skin and deliver the insulin subcutaneously
  • Insulin pumps: these are small computerized devices that deliver a continuous supply of insulin under the skin. They are also known as continuous subcutaneous insulin infusion devices (CSII)
  • Via a syringe and needle using a vial of insulin.

So far, nobody has successfully made an oral insulin tablet that delivers an effective dose of insulin. The problem is that insulin degrades in the stomach and intestine before it even has a chance to get absorbed into the blood stream. In hospital, insulin may be administered directly into a vein or into a muscle under certain circumstances.

What are the side effects of insulin?

One of the most common side effects of insulin is hypoglycemia (also called low blood sugar).

Symptoms include a headache, sweating, trembling, anxiety, confusion, irritability, rapid breathing, or a fast heartbeat. People with hypoglycemia may also faint and severe hypoglycemia that is left untreated may be fatal.

Hypoglycemia is relatively common because insulin requirements can vary depending on the food you eat, exercise you do, and how well you are. Hyperglycemia (high blood sugar levels) from too low an insulin dose can also occasionally occur.

Other common side effects include:

  • swelling, itching, redness or lumps around the injection site
  • weight gain
  • electrolyte disturbances (including low potassium and low magnesium levels)
  • blurred vision (usually temporary).

Insulin analogues are less likely to cause weight gain or low night-time blood sugar levels than standard human insulins.

How long does insulin last for?

Insulin is easily broken down by extreme temperatures, which means you need to be careful if you live in a part of the U.S. that gets very hot in summer, or very cold in winter.

Opened and in-use cartridges and vials are fine to keep at room temperature (59 to 77 degrees Fahrenheit [15-25 degrees Celcius]) for up to 28 days. The exception is Tresiba which, once in use, is stable for up to 8 weeks at room temperature. If you are going out in the sun, always use an insulated bag protected by a cool pack to ensure your insulin doesn't heat up; but avoid freezing it. During cold weather, keep your insulin supplies close to your skin so your body heat keeps them at a more even temperature.

All unopened vials and cartridges should be kept in the fridge, between 36-46 degrees Fahrenheit (2-8 degrees Celcius). Discard any insulin that you think may have inadvertently got too hot or too cold. The expiry date on insulin applies to unopened, refrigerated insulin.

What else should I know about insulin?

Our insulin requirements vary depending on the food we eat, how much activity we do, our general and mental health, how much we currently weigh, and our age.

Talk to your doctor about how you should adjust your insulin dose when you:

  • Are prescribed other medications (such as prednisone) that may affect your body's sensitivity to insulin
  • Are unwell or have an infection
  • Feel stressed or exceptionally tired
  • Gain or lose weight
  • Reduce or increase your activity levels
  • Are trying for a baby or find out you are pregnant.

You should also regularly monitor your blood glucose levels and be able to count your calories (particularly carbohydrates) and know how to calculate how much insulin to take and when to adjust it. If you don't know how to do this, ask your doctor or talk to a diabetes nurse.

You should know what to do if your blood sugar level goes too high or too low and have an action plan in place so that your family and friends also know what to do.

Most insulin in the U.S. is sold as a concentration of 100 units per ml (U100). However, there are currently four concentrated products on the market:

  • Humulin R (human insulin) which has a 500 units per ml (U500) strength available
  • Humalog (insulin lispro) which has a 200 units per ml (U200) strength available
  • Toujeo Solostar which contains 300 units per ml (U300) of insulin glargine
  • Tresiba (insulin degludec) which has a 200 units per ml (U200) strength available.

References

  1. 1 in 3 With Type 1 Diabetes Produce Insulin: Study. Web MD. http://www.webmd.com/diabetes/news/20141229/1-in-3-people-with-type-1-diabetes-still-produce-insulin-study-says#2
  2. Cantley J, Ashcroft FM. Q&A: insulin secretion and type 2 diabetes: why do β-cells fail? BMC Biology. 2015;13:33. doi:10.1186/s12915-015-0140-6
  3. Leontis L, Hess-Fischl. Type 2 Diabetes.  Causes, Genetics and Lifestyle Choices Play a Role. Endocrine Web. https://www.endocrineweb.com/conditions/type-2-diabetes/type-2-diabetes-causes
  4. Liamis G, Liberopoulos E, Barkas F, Elisaf M. Diabetes mellitus and electrolyte disorders. World Journal of Clinical Cases : WJCC. 2014;2(10):488-496. doi:10.12998/wjcc.v2.i10.488.
  5. MacGill M. Discovery of Insulin. Medical News Today 2016. http://www.medicalnewstoday.com/info/diabetes/discoveryofinsulin.php
  6. Martin JH, Russell A, O’Moore-Sullivan T, Prins JB (2011) Insulin Analogues: Reviewing the Pros and Cons in Managing Diabetes Mellitus. J Pharmacogenomics Pharmacoproteomics 2:106. doi: 10.4172/2153-0645.1000106
  7. Quianzon CC, Cheikh I. History of insulin. Journal of Community Hospital Internal Medicine Perspectives. 2012;2(2):10.3402/jchimp.v2i2.18701. doi:10.3402/jchimp.v2i2.18701.
  8. Type 1 diabetes. Mayo Clinic. http://www.mayoclinic.org/diseases-conditions/type-1-diabetes/diagnosis-treatment/treatment/txc-20340999
  9. Type 2 diabetes Medline Plus. US National Library of Medicine. https://medlineplus.gov/ency/article/000313.htm
  10. Types of Insulin. Diabetes Education Online. UCSF Medical Center. https://dtc.ucsf.edu/types-of-diabetes/type2/treatment-of-type-2-diabetes/medications-and-therapies/type-2-insulin-rx/types-of-insulin/

 

List of Insulin:

View by  Brand | Generic
Drug Name Avg. Rating Reviews
Tresiba (Pro)
Generic name: insulin degludec
4.4
131 reviews
Basaglar (Pro)
Generic name: insulin glargine
2.5
128 reviews
Toujeo SoloStar (Pro)
Generic name: insulin glargine
4.2
44 reviews
Levemir (Pro)
Generic name: insulin detemir
6.2
39 reviews
Lantus (Pro)
Generic name: insulin glargine
7.2
39 reviews
Afrezza (Pro)
Generic name: insulin inhalation, rapid acting
5.8
31 reviews
Lantus SoloStar
Generic name: insulin glargine
7.7
29 reviews
Humalog KwikPen
Generic name: insulin lispro
3.9
29 reviews
Novolog
Generic name: insulin aspart
6.1
21 reviews
Humalog (Pro)
Generic name: insulin lispro
7.2
18 reviews
Admelog (Pro)
Generic name: insulin lispro
2.1
14 reviews
Humulin R U-500 (Concentrated) (Pro)
Generic name: insulin regular
7.1
7 reviews
Novolin N (Pro)
Generic name: insulin isophane
8.3
6 reviews
Novolin R (Pro)
Generic name: insulin regular
6.5
5 reviews
Novolin 70 / 30 (Pro)
Generic name: insulin isophane / insulin regular
8.1
4 reviews
NovoLog Mix 70 / 30
Generic name: insulin aspart / insulin aspart protamine
9.5
3 reviews
NovoLog FlexPen
Generic name: insulin aspart
8.8
3 reviews
Humulin R U-500 KwikPen
Generic name: insulin regular
6.8
3 reviews
Humulin N Pen
Generic name: insulin isophane
8.0
3 reviews
Humulin N (Pro)
Generic name: insulin isophane
8.2
3 reviews
Humalog Mix 75 / 25
Generic name: insulin lispro / insulin lispro protamine
9.3
3 reviews
Fiasp (Pro)
Generic name: insulin aspart
8.3
3 reviews
Exubera (Pro)
Generic name: insulin inhalation, rapid acting
8.8
3 reviews
Apidra (Pro)
Generic name: insulin glulisine
8.1
3 reviews
Ryzodeg 70 / 30
Generic name: insulin aspart / insulin degludec
7.0
2 reviews
Semglee (Pro)
Generic name: insulin glargine
1.0
1 review
ReliOn / Novolin 70 / 30
Generic name: insulin isophane / insulin regular
9.5
1 review
NovoLog Mix 70 / 30 FlexPen
Generic name: insulin aspart / insulin aspart protamine
10
1 review
Humulin R (Pro)
Generic name: insulin regular
9.5
1 review
Humulin 70 / 30 (Pro)
Generic name: insulin isophane / insulin regular
6.7
1 review
Toujeo Max SoloStar
Generic name: insulin glargine
No reviews
Rezvoglar
Generic name: insulin glargine
No reviews
NovoLog PenFill
Generic name: insulin aspart
1.0
No reviews
Myxredlin
Generic name: insulin regular
No reviews
Lyumjev (Pro)
Generic name: insulin lispro
No reviews
Humulin U
Generic name: insulin zinc extended
No reviews
Humulin L
Generic name: insulin zinc
No reviews
Humulin 70 / 30 Pen
Generic name: insulin isophane / insulin regular
No reviews
Humulin 50 / 50 (Pro)
Generic name: insulin isophane / insulin regular
7.0
No reviews
Humalog Mix 75 / 25 KwikPen
Generic name: insulin lispro / insulin lispro protamine
7.5
No reviews
Humalog Mix 50 / 50 KwikPen
Generic name: insulin lispro / insulin lispro protamine
No reviews
Humalog Mix 50 / 50
Generic name: insulin lispro / insulin lispro protamine
No reviews
For ratings, users were asked how effective they found the medicine while considering positive/adverse effects and ease of use (1 = not effective, 10 = most effective).

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.