Chest
Volume 124, Issue 6, December 2003, Pages 2178-2181
Journal home page for Chest

Clinical Investigations
COUGH
Effect of Guaifenesin on Cough Reflex Sensitivity

https://doi.org/10.1378/chest.124.6.2178Get rights and content

Background

Guaifenesin, a commonly used agent for the treatment of cough, is termed an expectorant since it is believed to alleviate cough discomfort by increasing sputum volume and decreasing its viscosity, thereby promoting effective cough. Despite its common usage, relatively few studies, yielding contrasting results, have been performed to investigate the action and efficacy of guaifenesin.

Study objectives

To evaluate the effect of guaifenesin on cough reflex sensitivity.

Design

Randomized, double-blind, placebo-controlled trial.

Setting

Academic medical center.

Participants

Fourteen subjects with acute viral upper respiratory tract infection (URI) and 14 healthy volunteers.

Interventions

On 2 separate days, subjects underwent capsaicin cough challenge 1 to 2 h after receiving a single, 400-mg dose (capsules) of guaifenesin or matched placebo.

Measurements and results

The concentration of capsaicin inducing five or more coughs (C5) was determined. Among subjects with URI, mean (± SEM) log C5 after guaifenesin and placebo were 0.92 ± 0.17 and 0.66 ± 0.14, respectively (p = 0.028). No effect on cough sensitivity was observed in healthy volunteers.

Conclusions

Our results demonstrate that guaifenesin inhibits cough reflex sensitivity in subjects with URI, whose cough receptors are transiently hypersensitive, but not in healthy volunteers. Possible mechanisms include a central antitussive effect, or a peripheral effect by increased sputum volume serving as a barrier shielding cough receptors within the respiratory epithelium from the tussive stimulus.

Section snippets

Subjects

Fourteen healthy volunteers (5 men and 9 women; mean age ± SEM, 36.1 ± 1.2 years), as well as 14 otherwise healthy subjects with symptoms consistent with URI (4 men and 10 women; mean age, 30.8 ± 1.2 years) were recruited for the study, which was approved by the Institutional Review Board of Albert Einstein Hospital/Montefiore Medical Center. All participants were nonsmokers without a history of pulmonary disease, and without history or symptoms suggestive of gastroesophageal reflux. Healthy

Results

The induction of five or more coughs was achieved in all participants. In subjects with URI, there were no significant differences in pulmonary function values (FVC, FEV1, and forced expiratory flow, midexpiratory phase) after guaifenesin and placebo. In terms of cough sensitivity, mean log C5 after guaifenesin was significantly higher than after placebo: 0.92 ± 0.17 and 0.66 ± 0.14, respectively (p = 0.028). Seven of 14 subjects demonstrated a two doubling-concentration increase in C5 after

Discussion

The present study has demonstrated that a single, 400-mg dose of guaifenesin inhibits cough reflex sensitivity to inhaled capsaicin in subjects with acute viral URI. In contrast, cough sensitivity was not altered by guaifenesin in healthy volunteers. Thus, the observed antitussive effect of guaifenesin appears limited to subjects in whom cough receptor sensitivity is enhanced, in this case by the presence of a viral URI. To the best of our knowledge, the only prior study16 that has evaluated

References (20)

There are more references available in the full text version of this article.

Cited by (84)

  • The effect of oral guaifenesin on pediatric chronic rhinitis: A pilot study

    2023, American Journal of Otolaryngology - Head and Neck Medicine and Surgery
  • Cough and Common Cold

    2022, Comprehensive Pharmacology
  • Silver nanoparticles/poly(L-cysteine) nanocomposite modified pencil graphite for selective electrochemical measurement of guaifenesin in real samples

    2021, Measurement: Journal of the International Measurement Confederation
    Citation Excerpt :

    Guaifenesin (GF) named 3-(2-methoxyphenoxy)-propane-1,2-diol (Fig. 1) is known as an expectorant medicine that has been used to treat the symptoms of coughs caused by cold and mild upper respiratory tract infections such as pharyngitis, sinusitis and bronchitis [1]. By reducing the adhesion of the secretions and diluting them, guaifenesin increases the outflowing secretions of the respiratory system and allows the ciliary to move them toward the pharynx [2]. It increases the efficacy of the mucociliary mechanism in removing accumulated secretions and cause from the upper and lower airway which makes breathing easier.

  • Antitussive, expectorant, and anti-inflammatory effects of Adenophorae Radix powder in ICR mice

    2019, Journal of Ethnopharmacology
    Citation Excerpt :

    Cough can occur either as a non-productive (dry) or productive (chesty) cough (Dapaah et al., 2016). Non-productive coughing is treated effectively by antitussive drugs, which are not as effective against productive coughing unless the antitussive also exhibits expectorant properties (Dicpinigaitis and Gayle, 2003). In addition, inflammatory processes have been involved in the pathogenesis of various respiratory disorders (Sanak, 2016; Woloski et al., 2016).

  • Voltammetric method for simultaneous determination of ascorbic acid, paracetamol and guaifenesin using a sequential experimentation strategy

    2019, Microchemical Journal
    Citation Excerpt :

    GU is used as expectorant. It reduces the viscosity of bronchial secretions [29,30]. Fig. 1 shows the chemical structure of investigated drugs.

View all citing articles on Scopus

Supported by a grant from Procter & Gamble.

Presented in part at the American Thoracic Society International Conference, Seattle, WA, May 20, 2003.

View full text