From the Guidelines
Carbocysteine is a safe and effective mucolytic agent for reducing exacerbations in chronic obstructive pulmonary disease (COPD) and chronic bronchitis, with a typical adult dosage ranging from 750mg to 1500mg daily, divided into 2-3 doses. The evidence from recent studies, such as the 2017 European Respiratory Society/American Thoracic Society guideline 1, suggests that mucolytic therapy, including carbocysteine, can reduce the likelihood of hospitalization and COPD exacerbations. Additionally, the 2017 Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Lung Disease report 1 notes that regular use of mucolytics, such as carbocysteine and N-acetylcysteine, may reduce exacerbations and modestly improve health status in patients not receiving inhaled corticosteroids.
The mechanism of action of carbocysteine involves modifying the structure of mucus glycoproteins, restoring the balance between sialomucins and fucomucins, and has additional anti-inflammatory and antioxidant properties that may contribute to its therapeutic effects 1. The side effects of carbocysteine are generally mild and may include gastrointestinal disturbances like nausea, stomach discomfort, and diarrhea, with rare allergic reactions occurring 1. It is essential to use carbocysteine with caution in patients with gastric ulcers and avoid its use during pregnancy unless clearly necessary.
Key points to consider when using carbocysteine include:
- Reduces exacerbations in COPD and chronic bronchitis
- Typical adult dosage: 750mg to 1500mg daily, divided into 2-3 doses
- Mild side effects, including gastrointestinal disturbances and rare allergic reactions
- Use with caution in patients with gastric ulcers and avoid during pregnancy unless necessary
- Additional anti-inflammatory and antioxidant properties may contribute to its therapeutic effects
Overall, the evidence supports the use of carbocysteine as a safe and effective mucolytic agent for reducing exacerbations in COPD and chronic bronchitis, with a favorable safety profile and potential additional benefits beyond its mucolytic effects.
From the FDA Drug Label
ACETYLCYSTEINE AS A MUCOLYTIC AGENT CLINICAL PHARMACOLOGY The viscosity of pulmonary mucous secretions depends on the concentrations of mucoprotein and, to a lesser extent, deoxyribonucleic acid (DNA). The mucolytic action of acetylcysteine is related to the sulfhydryl group in the molecule This group probably “opens” disulfide linkages in mucous thereby lowering the viscosity. The mucolytic activity of acetylcysteine is unaltered by the presence of DNA, and increases with increasing pH. Significant mucolysis occurs between pH 7 and 9.
The efficacy of carbocysteine (acetylcysteine) as a mucolytic agent is related to its ability to break down disulfide linkages in mucous, thereby lowering its viscosity.
- The mucolytic activity of acetylcysteine is most significant between pH 7 and 9.
- It is indicated for use in patients with abnormal, viscid, or inspissated mucous secretions in various conditions, including chronic bronchopulmonary disease and pulmonary complications of cystic fibrosis. The safety of carbocysteine (acetylcysteine) is generally considered to be good, but it can cause adverse effects such as:
- Stomatitis
- Nausea
- Vomiting
- Fever
- Rhinorrhea
- Drowsiness
- Clamminess
- Chest tightness
- Bronchoconstriction It is contraindicated in patients who are sensitive to it, and should be used with caution in patients with asthma. 2 2 2
From the Research
Efficacy of Carbocysteine
- Carbocysteine has been recognized as an effective treatment for the long-term management of chronic obstructive pulmonary disease (COPD), able to reduce the incidence of exacerbations and improve patient quality of life 3.
- A systematic review and meta-analysis found that carbocisteine decreased the risk of the rate of total number of exacerbations with carbocisteine compared with placebo, and improved the quality of life of patients with COPD 4.
- However, a multicentre, double-blind, randomized, placebo-controlled trial found that carbocysteine might not significantly reduce the annual rate of total exacerbations in patients with mild-to-moderate COPD 5.
Safety of Carbocysteine
- Carbocysteine has been found to have a favorable safety profile, with no significant difference in adverse effects compared to placebo 4, 5.
- A review of 72 articles found that the use of carbocysteine in COPD patients represents a well-tolerated treatment with a favorable safety profile 6.
Mechanisms of Action
- Carbocysteine has been found to have antioxidant and anti-inflammatory properties, which are more important than mucolysis itself for its therapeutic efficacy 3.
- Carbocysteine is able to modulate mucins and ciliary functions, and to counteract viral and bacterial infections as well as oxidative stress, offering cytoprotective effects 6.
- Carbocysteine improves steroid responsiveness and exerts anti-inflammatory activity, which may contribute to a better quality of life for patients suffering from COPD 6.