Mucolytics: Uses, common brands, and safety info

Mucolytics are a class of medications that are used to thin mucus in the airways. Excessive mucus production can be a sign that a respiratory condition is worsening, whether it's an acute exacerbation or a short-term illness. Mucolytics can make the mucus in the respiratory tract thinner and less sticky, especially when mucus is thick and hard to cough up. These medications help treat chest congestion and a productive cough associated with respiratory conditions like chronic obstructive pulmonary disease (COPD), cystic fibrosis, and bronchiectasis. 

Continue reading to learn more about mucolytics, their uses, and their side effects.

Other mucolytics

• Erdotin (erdosteine)

• Bronchitol (mannitol)

• Thymosin beta-4

• Cleanal (fudosteine)

• Hypertonic saline

• Mucolyte (bromhexine)

What are mucolytics?

Mucolytics are part of a broader group of drugs called mucoactive agents, and they are used to manage mucus production caused by chronic respiratory conditions. This group of drugs comprises different medications that may work in different ways and be used for different purposes. Some mucolytics may have antioxidant and anti-inflammatory effects, while others have additional expectorant or antitussive actions. Although they may work in different ways, mucolytics are typically prescribed for a similar purpose: thinning excess mucus to clear it from the lungs.

Most mucolytics are administered as an oral medication, although they can also be administered through intravenous and nebulizer formulations. For example, carbocysteine and erdosteine are typically given as oral doses for respiratory diseases. N-acetylcysteine and dornase alfa are often inhaled through a nebulizer in people with cystic fibrosis or similar conditions. 

Mucolytics may also be given along with other medications, depending on the condition being treated. For example, dornase alfa is typically prescribed along with antibiotics for cystic fibrosis. Mucolytics may be also administered in combination with another mucoactive agent, such as an expectorant, to help treat a productive cough. Mucinex (guaifenesin), for example, is an expectorant that helps thin and loosen mucus in the airways, making it easier to cough up and clear out. Combining mucoactive agents can help manage airway secretions and promote mucus clearance.

How do mucolytics work?

Mucus is normally produced in the lungs and airways to act as a lubricant and protective barrier against pathogens. Mucus is one of the body's first lines of defense against harmful pathogens, such as bacteria and viruses, that cause infection. It is formed by the cross-bridging of gel-forming proteins called mucins. These proteins create a mucus layer, which helps control the growth and spread of bacteria while also providing a physical barrier against respiratory irritants. 

Sputum, or phlegm, is the mucus that is produced specifically in the lungs and airways. It can be thick, sticky, and hard to cough up. Large amounts of mucus can decrease lung function and make it harder to breathe. 

Mucolytics thin the mucus in the lungs and airways by breaking down its structure. More specifically, they work to break down the bonds that hold mucoproteins together. When these bonds are broken, the mucus is thinned and able to be moved out of the airways more easily. 

What are mucolytics used for?

Mucolytics are commonly used to treat chronic respiratory conditions that are characterized by periods of excess mucus production, or mucus hypersecretion. However, they can also be used to help clear mucus caused by short-term worsening of respiratory conditions, such as COPD exacerbations. The uses of mucolytics may include the following:

• COPD, such as emphysema and chronic bronchitis

• Cystic fibrosis

• Bronchiectasis

• Pneumonia

• Tuberculosis

• Common cold

• Diagnostic bronchial studies

• Dietary supplementation

• Acetaminophen overdose

In addition, certain mucolytics may be indicated for other reasons, including acetaminophen overdose and diagnostic bronchial studies. For example, N-acetylcysteine is used to help treat people who have taken too much acetaminophen by breaking down mucus and protecting the liver. On the other hand, hypertonic saline is a saltwater solution that doctors use during lung tests to clear out mucus and improve visibility in the airways.

Types of mucolytics

There are two types of mucolytic agents: classic and peptide mucolytics. 

Classic mucolytics

The classic mucolytics work by breaking down the mucin network that initially forms the mucus layer. By breaking down the structures that hold mucus together, the classic mucolytics make sputum easier to expel from the airways. The classic mucolytics include N-acetylcysteine, carbocysteine, erdosteine, and fudosteine. 

Peptide mucolytics

Peptide mucolytics do not attack the mucin network found in the mucus layer. Instead, they target the protein and DNA links that are typically found in pus. Peptide mucolytics are useful for thick, purulent mucus that is characteristic of cystic fibrosis, which is often associated with respiratory infections. The peptide mucolytics include dornase alfa and thymosin beta-4. 

Who can take mucolytics?

Adults

Mucolytic agents may be prescribed to adults with chronic respiratory conditions, such as COPD and chronic bronchitis. Clinical trials have shown that the use of mucolytic drugs may result in fewer flare-ups in patients with COPD or chronic bronchitis when compared to placebo. There were few side effects experienced by those taking mucolytic drugs. Earlier studies also found that mucolytics may help improve quality of life. 

Mucolytics work best when taken on a regular schedule, and several doses may need to be taken throughout the day. They come in different forms, including inhalation solutions, intravenous solutions, effervescent tablets, regular tablets, capsules, and liquids. When using mucolytics as an inhalation solution, a device called a nebulizer is used to turn the medicine into a mist for easier breathing. Healthcare providers often suggest using a bronchodilator, which helps open up the airways, before taking the mucolytic to make it work better. Infants, children, and adolescents may safely take mucolytics. Dornase alfa is used to treat cystic fibrosis and is administered with a nebulized inhalation solution. In young children and infants, dornase alfa has been shown to be beneficial for cystic fibrosis, improving lung function in trials lasting from one month to two years.

N-acetylcysteine may be administered to children via a nebulizer or an enema. If given for Tylenol overdose, an N-acetylcysteine dose is calculated according to the child’s weight. 

Seniors

Older adults may safely take mucolytics. Dosing is the same as for adults and does not require adjustment. 

Can you take mucolytics while pregnant or breastfeeding?

Mucolytics are generally safe for use during pregnancy. Certain mucolytic agents, such as N-acetylcysteine, may be preferred over others during pregnancy. While the risk of harm while using mucolytics during breastfeeding is low, mucolytics should only be used when necessary or if the benefits outweigh the potential risks. Consult a healthcare provider before using a mucolytic drug while pregnant or breastfeeding. 

Are mucolytics safe?

In general, mucolytics are safe and well-tolerated. Toxicity with mucolytics is rare and most often associated with intravenous administration of the medications. Certain groups of people should avoid mucolytics or be monitored for adverse effects during treatment.

Tell your healthcare provider if you have a history of any of the following before taking a mucolytic:

• Peptic ulcer disease

• Esophageal varices

• Gastric ulcers

• Use of other medications

• Allergic reactions to mucolytic agents 

• Allergic reactions to Chinese Hamster Ovary cell products

Mucolytic recalls

There are no current mucolytic drug recalls.

Mucolytic restrictions

Adults and children with allergies to Chinese Hamster Ovary cell products should avoid the use of Pulmozyme or dornase alfa. 

N-acetylcysteine is not recommended for use in people with peptic ulcers, esophageal varices, or similar conditions. Mucolytics may cause vomiting, which may worsen these conditions. 

Talk to a healthcare provider to determine other potential restrictions associated with mucolytics. 

Are mucolytics controlled substances?

No, mucolytics are not controlled substances.

Common mucolytics side effects

Side effects of mucolytics can vary depending on the drug and formulation. The most common adverse effects of mucolytics may include:

• Nausea

• Vomiting

• Upset stomach

• Diarrhea

• Headache

• Fever

• Runny nose

• Sore throat

• Drowsiness

• Rash

More severe but rare side effects include:

• Chest tightness

• Trouble breathing

• Gastric bleeding or ulcers

In rare cases, mucolytics may cause hypersensitivity or allergic reactions. Seek immediate medical attention if you experience signs of an allergy reaction, such as severe rash or swelling of the face or throat. 

This list of side effects is not comprehensive. Side effects are generally mild and self-limiting, and mucolytics are widely considered safe for use in adults and children of all ages. Talk to your healthcare provider if you experience side effects that are particularly bothersome during treatment. 

Consult a healthcare provider for a complete list of side effects, warnings, and precautions before starting treatment with a mucolytic.

How much do mucolytics cost?

Mucolytics are available in brand-name and generic formulations. Most Medicare and insurance plans will cover the generic versions of mucolytic agents. However, costs will vary depending on the insurance plan. Talk to your pharmacist or insurance company directly to determine the exact cost of your medication through your insurance plan. Without insurance, the price can vary widely depending on the medication and quantity of medication prescribed. Using a prescription discount card from SingleCare may help reduce the cost of mucolytics like acetylcysteine and Availnex.