Role of guaifenesin in the management of chronic bronchitis and upper respiratory tract infections

H. H. Albrecht, P.V Dicpinigaitis, E. P. Guenin

Multidiscip Respir Med. 2017. 12:31

Overview:

Guaifenesin, a mucoactive drug, loosens mucus in the airways and makes coughs more productive. An ingredient in many OTC cough/cold medications, it is used for relief of wet cough and chest congestion due to the common cold and remains the only FDA-approved expectorant in the United States.

Indications:

Clinical pharmacology and patient studies support the clinical use of guaifenesin in respiratory conditions where mucus hypersecretion is prevalent: acute upper respiratory tract infections (URTIs) and chronic respiratory conditions, including stable chronic bronchitis (SCB). Excess mucus is an underlying cause of congestion in SCB.

Key Findings:

Effects of guaifenesin on mucus in chronic or acute hypersecretory respiratory conditions.

Adapted from Albrecht H, et al. Role of guaifenesin in the management of chronic bronchitis and upper respiratory tract infections. Multidiscip Respir Med 12, 31 (2017).

Guaifenesin has been postulated to promote mucociliary clearance via a number of mechanisms. (1) indirect activation/stimulation of gastrointestinal vagal afferent nerves triggers reflex parasympathetic glandular secretion from submucosal glands and goblet cells (green stars), increasing hydration of mucus layer for more effective mucociliary clearance. Guaifenesin also affects secretion from goblet and Clara cells (red stars), resulting in (2) decreased mucin production and secretion (green circles, goblet cells; blue squares, Clara cells), and (3) reduced viscoelasticity of mucus, which increases the ability of ciliary movement to remove mucus.

Dosing:

Dosing range (200–400 mg every 4 hours) allows for flexible dose titration. Extended-release guaifenesin tablet formulations are available, providing convenience with 12-hour dosing and portability compared to liquids.

Safety and Efficacy:

Guaifenesin is considered a safe and effective expectorant for the treatment of mucus-related symptoms in acute URTIs and SCB. Its clinical efficacy has been demonstrated most widely in chronic respiratory conditions, where excess mucus production and cough are more stable symptoms.

Conclusions:

These data support the use of guaifenesin in treating respiratory disorders in which excessive mucus is an important clinical feature

Excessive mucus secretion and local accumulation in the airway occurs in both acute URTIs and chronic respiratory disorders with an underlying inflammatory etiology (such as chronic bronchitis and COPD)
The expectorant properties of guaifenesin, which help to thin bronchial secretions and promote mucus clearance, were demonstrated in studies involving patients with chronic bronchitis or other chronic respiratory conditions
These studies played an important role in the FDA’s decision to include guaifenesin as an expectorant in the respective Final OTC Monograph labeled for the relief of mucus-related symptoms of acute URTIs and stable chronic bronchitis

The FDA “determines whether medicines are prescription or nonprescription.”¹ This review of guaifenesin, the only FDA-approved expectorant in the US and the active ingredient in MUCINEX®, concludes that the data support its use in respiratory disorders where excessive mucus is an important clinical feature, such as acute URTIs and stable chronic bronchitis. Studies in patients with chronic bronchitis or other chronic respiratory conditions played an important role in the FDA’s decision to include guaifenesin as an expectorant in the Final OTC Monograph.²