Inhaled Insulin

Introduction

Many diabetic patients will express how much they dislike having to give themselves constant subcutaneous injections of insulin. For decades scientists and drug companies have worked together to find a more comfortable way for these patients to receive insulin.

Since the 1980´s studies showed that inhaled insulin could be as effective as subcutaneous insulin but due to complications of how to administer it there was a pause in production. ⁽²⁾ As recent as 2014 it appears that they now have that alternative. ⁽¹⁾

Pros and Cons

Pros

1. Fewer injections for the patient

2. Easier administration

3. Fewer materials needed

4. The lungs provide a large vascular area for quicker absorption of the drug.

5. Better adherence to treatment regimens

Cons

1 . Possible damage to lung tissue

2. The need for lifestyle changes is still necessary

3. Higher costs

4. Due to the nature of inhaled medications appropriate dosage can be an issue. Topics of discussion regarding appropriate delivery are:

• Particle speed
• Particle size
• Ventilatory parameters
• Patient participation and correct inhalation maneuvers
• Loss of the drug in the device chamber or in the upper airway

5. Many of the medical studies have been halted due to the experience of Pfizer with Exubera. ⁽²⁾

 

Brands

Exubera was the first inhaled insulin placed on the market in 2006. This inhaled insulin could be used for both Type I & II diabetes. Common know facts about this brand are as follows:

• Was developed with Nektar Therapeutics and Pfizer working together.
• Was taken off the market initially due to low sales only one year after its initiation on the market.
• The inhaler was felt to be very uncomfortable for the user
• After being taken off the market the FDA found evidence that it could cause lung problems or even lung cancer. ^(8,9,10)

Afrezza is the newest brand of inhaled insulin available. Here are some of its most commonly known facts.

• Mannkind Corporation in Connecticut is the responsible manufacture.
• FDA approved in 2016 to be used before meals, not for diabetic crisis ⁽⁴⁾

FDA is requiring a serious of post-market evaluations of the drug. This meaning that the medical studies have not ended and must be reported to the FDA.

• It is a rapid-acting insulin
• As with any drug it has common side effects which will be stated bellow.
• It is to be used in combination with healthy lifestyles such as proper diabetic diet and exercise.
• In the case of Type I other long-acting insulins may be prescribed as well. ^(1,3,4)
• If the patient has any history of lung issues this type of insulin should not be used. ^(1,3)
• The same information that is to be found on the package insert can also be found on the Aferzza web page and includes information such as:

1. Information regarding usage
2. Patient education
3. Actions
4. Contraindications
5. Dosage information
6. Side effects⁽³⁾

Below is a table showing the different companies that have addressed inhaled insulin and their outcomes.

 

Picture 1: Inhaled insulin systems
Image Source: ncbi.nlm.nih.gov

Note the images below which show the difference in size and connivance between first trials of inhaled insulin and present ones. The fist image is from Exubera and the second is Aferzza.

Exubera Insulin Inhaler
Image Source: nature.com

Photo 3: Aferzza insulin inhaler
Image Source: healthline.com

Mechanism of Action : Inhaled insulin

Most studies place inhaled insulin in the same category as Regular insulin. Its action is not a sustained control over glucose level rather a rapid effect lasting between 30-60 minutes.^(2,3)

Most common Side effects

• Sudden or serious lung problems ⁽⁵⁾
• Changes in diabetic lab results
• Hypoglycemia  low blood sugar
• Cough
• This table gives a more detailed description of each side effect.^(2,3)

 

Image Source: ncbi.nlm.nih.gov

• Alert your doctor in the case of any of the following symptoms:

1. Trouble breathing
2. Chest tightness
3. Severe coughing
4. Wheezing
5. Swelling in feet or hands
6. Rapid weight gain
7. Confusion
8. Palpitations
9. Muscle weakness
10. Leg discomfort ⁽⁵⁾

Contraindications

• Insulin allergies ⁽⁵⁾
• Smokers or those exposed to second hand smoke on a constant basis
• Diagnosis of COPD
• History of lung cancer
• Asthma ^(2,3)
• Hypersensitivity to Regular Insulin ⁽³⁾
• Alert your physician if you have any of the following diagnosis in order to assist in the proper administration and usage of the medication.

1. Any electrolyte imbalance
2. Kidney or liver issues
3. Any heart-related issues or disease.
4. Always advise your doctor of any medications you are taking.
5. If you are pregnant or currently breastfeeding.⁽⁵⁾

Usage

• Diabetes mellitus Type I &II ^(2,3)
• Alternative usages

1. Alzheimer’s In 2010 a small study was done over a four month time period was done on Alzheimer patients concluding that twice a day dosage of inhalable insulin increased memory. The study was done on 100 patients showing very few side effects and an overall increase in brain function. ^(12–13)
2. According to the Mayo clinic, much more study is needed to make a positive conclusion. They also state that very few medical professionals are suggesting the use of insulin for Alzheimer patients. ⁽¹⁴⁾

Dosage

• Exactly as prescribed by your doctor.
• At meal times
• In the case that you forget a dose, take your prescribed dose as prescribed as soon as you remember
• In the case of overdose seek emergency attention. Symptoms may be as follows:

1. Trouble speaking
2. Blurred vision
3. Confusion
4. Seizures
5. Tremors
6. Extreme weakness. ⁽⁵⁾

Inhaled insulin PPT – link

References:

1. http://www.webmd.com/diabetes/guide/inhaled-insulin
2. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2835554/
3. https://www.afrezza.com/hcp
4. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm403122.htm
5. https://www.drugs.com/afrezza.html
6. http://www.webmd.com/diabetes/news/20140630/inhaled-insulin-afrezza
7. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm403113.htm
8. http://www.webmd.com/diabetes/news/20071018/pfizer-quits-inhaled-insulin-exubera
9. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321660/
10. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2769732/
11. http://www.webmd.com/alzheimers/news/20100714/insulin-nasal-spray-may-help-treat-alzheimers
12. http://www.washingtonpost.com/wp-dyn/content/article/2010/07/14/AR2010071403990.html
13. http://www.mayoclinic.org/diseases-conditions/alzheimers-disease/expert-answers/alzheimers-nose-spray/FAQ-20058557
14. http://www.jci.org/articles/view/64595