What People With Asthma Need to Know About Long-Acting Muscarinic Antagonists (LAMAs)

Are you wondering what the heck a long-acting muscarinic antagonist (LAMA, for short) even is? If so, I had the same thought first time I heard that term. Turns out it's simply a type of asthma medication that is recommended for certain people. But let's give it some context first.

Revisions to our national asthma guidelines

In December 2020, the national panel of experts tasked with guiding health care professionals on how to best treat asthma revised their official guidelines. This is important because it's the first time the asthma treatment guidelines have been revised since 2007. In the years since, researchers have learned quite a bit more about the origins of asthma and how the disease changes over time. New medications have also been approved during the last decade or so. So, updates to the guidelines were in order.¹

One of the areas of focus in the new guidelines is a class of drugs that to date has not been used extensively in asthma treatment. This type of medication is called a long-acting muscarinic antagonist. The revised guidelines cover how and when to incorporate LAMAs into asthma treatment plans for certain groups of people.¹

What is a long-acting muscarinic antagonist?

LAMAs are a class of inhaled bronchodilators that affect the airways for at least 12 hours (as opposed to giving rapid relief). Muscarinic refers to a type of receptor in smooth muscle cells such as those that line your airways. A muscarinic antagonist interferes with a neurotransmitter called acetylcholine that causes smooth muscle cells to contract. In other words, this type of medicine prevents airways from tightening and helps them to relax.^2,3

There are a variety of LAMAs currently available, but most of them are only used for people who have COPD, not asthma. Currently, only 1 LAMA medication is approved for use in treating asthma. It is tiotropium bromide, brand name Respimat.⁴

What is the difference between a LABA and a LAMA?

Another class of medications called long-acting beta-agonists (LABAs for short) is more commonly used in treating severe asthma. LABAs are also long-acting bronchodilators. Frequently, they are combined with an inhaled steroid, when the steroid alone does not sufficiently provide asthma control.⁴ Examples include formoterol and salmeterol.

Who needs a long-acting muscarinic antagonist?

In general, people who need more than an inhaled steroid to treat their asthma are those classified as having persistent, poorly-controlled asthma. These are people who have ongoing symptoms, even after consistently taking their inhaled steroids. Inhaled steroids stop and control the inflammation in the airways caused by asthma. But sometimes that is not enough to provide adequate asthma control.¹

The next step is to combine the inhaled steroid with a LABA, such as those listed above. Generally, this is done in a combination inhaler, under brand names such as Serevent and Symbicort. And yet, some severe asthmatics still are not able to achieve satisfactory asthma control even with one of those combinations.¹

So the next step may be to add a LAMA to the mix. In fact, a growing body of research evidence suggests that LAMAs can be useful in treating severe, uncontrolled asthma, even when added to a combination of both inhaled steroids and a LABA.⁵

How are LAMAs used in people with asthma?

However, the new Asthma Treatment Guidelines offer specific instructions as to the use of a long-acting muscarinic antagonist:⁴

• In children under age 12 and also in most of those age 12 or older with asthma that is not controlled by an inhaled corticosteroid alone, adding a LABA rather than a LAMA to an inhaled corticosteroid is preferred.
• For people age 12 years old and older who are not well-controlled with an inhaled steroid, either a LABA or LAMA may be added.
• When a combination of an inhaled steroid and a LABA does not produce asthma control in those age 12 and older, a LAMA may also be added.

Please note that the guidelines do not address the use of LAMAs at all in those under the age of 12 years.

Who should not use a LAMA for asthma?

For people who have severe uncontrolled asthma, it's always wise to be under the care of an asthma expert, who is familiar with all the available options. You should always be sure to thoroughly discuss and understand the risks vs. the benefits of any new treatment.

But here are a few cases where a LAMA is not recommended:⁴

• Children under the age of 12 years
• Anyone with glaucoma
• People with urinary retention

Do you use a LAMA for your or your child's asthma treatment? Share your thoughts and experiences in the comments below.