How Does Inhaled Insulin Work for Diabetes?

Insulin injections are a not-so-fun part of life for people with Type 1 diabetes and some with Type 2 diabetes. If there was an alternative available, like inhaled insulin, could it make living with diabetes easier?

That's one of the ideas behind Afrezza, an insulin inhalation powder that was approved by the U.S. Food and Drug Administration in 2014.

Inhaled insulin works faster than injected insulin because it reaches the lung tissue immediately upon inhalation, says Dr. David Klonoff, medical director of the Diabetes Research Institute at the Mills-Peninsula Medical Center in San Mateo, California. "From there it can diffuse into the bloodstream faster than an insulin molecule injected into the skin," he explains. That means the medication takes effect faster than injected insulin. In fact, its first measurable effect starts in about 12 minutes, and it has a peak effect in 35 to 45 minutes, according to information from the company website. It stops working in about 1.5 to 3 hours, depending on how much you've used.

[Read: 6 Ways to Save Money on Your Diabetes Medications.]

This faster action can help overcome mealtime challenges related to insulin absorption, says San Francisco-based Adam Brown, senior editor and columnist at diaTribe and author of "Bright Spots & Landmines: The Diabetes Guide I Wish Someone Had Handed Me."

In fact, the FDA recently updated the label for Afrezza to address how fast-acting it truly is, says Payal Marathe, senior associate at Close Concerns, which focuses on improving patient outcomes for those living with diabetes and obesity.

There are a few patients who may find inhaled insulin preferable to insulin injections. This includes patients with Type 1 diabetes who want to recover quickly from a very high blood sugar or Type 2 patients just starting on mealtime insulin, Brown says. It also could benefit patients eating a high-carb meal, those taking many bolus injections and anyone with a strong dislike of needles, Brown adds.

Some patients find mealtime insulin dosing challenging, and that's where this faster-acting type of insulin could help. "With inhaled insulin, it's possible to have less early hyperglycemia [high blood sugar], less late hypoglycemia [low blood sugar] and less glycemic variability," Klonoff says.

Another patient who may want to use inhaled insulin is someone with Type 1 diabetes who has a buildup of scar tissue at their injection sites or a person who wants to take a break from the use of an insulin pump, says Dr. Michael Castagna, CEO of MannKind, the maker of Afrezza.

[Read: 11 Tips for Testing Your Blood Sugar at Home.]

The product isn't yet approved for use in children, although the company is working on this for the future, Castagna says. Plus, using inhaled insulin doesn't mean you're necessarily free of injections. "In many cases, Afrezza users also will be on basal insulin therapy, which at this point is only injectable and would need to be taken separately," Marathe says. If you have Type 2 diabetes, you probably will still need to take some oral medications for diabetes.

There also are some patients who aren't well-suited for inhaled insulin, such as those who smoke or who have asthma or chronic obstructive pulmonary disorder, Castagna says.

Before you use inhaled insulin, you'll need to take a breathing test, called spirometry.

Some research has shown a small decline in lung function over several years in patients using inhaled insulin, Klonoff says. "However, studies of patients with diabetes who are not using this drug have shown a similar small decline," he adds.

If you and your health care professional decide that inhaled insulin is right for you, here are some tips to get adjusted.

Check with your insurance company about coverage. Insurance coverage is sometimes challenging, Castagna says. However, doctors' offices often find success if they appeal an initial decline. For the patient, the average copay is $35. There are discount cards from the company that lower the cost of the average prescription to $15, Castagna adds.

Get comfortable with the dosing. It can take a little trial and error to find the right dose for your meals. "The insulin comes in three multiples of four units -- blue four-unit cartridges, green eight-unit cartridges and yellow 12-unit cartridges -- so patients must learn how to match a meal with a dose that is in these multiples of four units," Klonoff says. "Each patient has a learning curve to translate their usual mealtime dose, which is typically dosed in one-unit increments, into a product with four-unit increments."

A patient who requires constant tweaks to their mealtime insulin routine may find insulin injections or an insulin pump easier to use than inhaled insulin, Brown says.

Ask for help. Work with your health care professional and certified diabetes educator to help target the right dosing for you. Many patients are sharing inhaled insulin tips on social media and through online diabetes support groups, Brown says. Of course, follow advice from your health team first.

Also, the use of a continuous glucose monitor can give you real-time numbers that show how your blood sugar is responding to inhaled insulin, Brown says.

[Read: 11 Ways to Save on Diabetes Supplies.]

Mind your insulin storage. Inhaled insulin is stored in the refrigerator per the package instructions; however, keep it out of the fridge for at least 10 minutes before you use it, Klonoff says.

Talk to your doctor if you get sick with a condition that affects the lungs, such as bronchitis. In that case, Klonoff recommends using injected insulin until the lungs have healed. It also should not be used during episodes of low blood sugar, Marathe says.

Vanessa Caceres is a Health freelancer for U.S. News. She's a nationally published health, travel and food writer, and she has an undergraduate degree in journalism and psychology from Hampshire College and a graduate degree in linguistics/bilingual education from Georgetown University. Connect with her on Twitter at @FloridaCulture.