Skip to main content

Table 3 Pharmacology studies

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

First Author (Year) Objectives of study Intervention Results
Chodosh (1973) To evaluate sputum changes associated with guaifenesin in chronic bronchial conditions Double-blind crossover study:
1 week known placebo +800 mg/day or 2400 mg/day for 4 weeks +1 week unknown placebo +1000 mL extra oral water intake
Significantly uniform and beneficial changes, such as sputum adhesiveness and dry weight, occurred with 2400 mg/day guaifenesin
Thomson (1973) To assess the effect of guaifenesin on mucociliary clearance (MCC) in the human lung from the rate of removal of inhaled radioactive tracer particles Double-blind crossover study:
600 mg guaifenesin vs placebo
Significant improvement in mucociliary clearance with guaifenesin in patients with chronic bronchitis but not in healthy subjects
Sisson (1995) To examine:
(i) The effect of guaifenesin on nasal MCC in vivo (assessed by saccharin transit time [STT]) and nasal ciliary beat frequency (CBF; assessed by nasal brushing and ex vivo microscopy), and
(ii) whether a relationship exists between nasal CBF and nasal STT
Double-blind crossover study:
400 mg guaifenesin vs placebo 5× daily from days 1 to 7, or days 14 to 21
No significant differences between guaifenesin- or placebo-treated groups in change from baseline values of STT or CBF
No relationship observed between STT and CBF from regression analysis
Dicpinigaitis (2003) To evaluate the effect of guaifenesin on cough reflex sensitivity to inhaled capsaicin in healthy subjects and subjects with acute URTIs Randomized double-blind study:
Single dose of 400 mg guaifenesin vs placebo
Cough reflex sensitivity was statistically significantly decreased with guaifenesin in patients with URTIs but not in healthy subjects
Dicpinigaitis (2009) To evaluate the antitussive effect of the combination of benzonatate and guaifenesin in subjects with acute URTI Randomized double-blind crossover study (n = 23):
Each subject received 3 of 4 possible study drug/combinations:
600 mg guaifenesin (G), 200 mg benzonatate (B), their combination (B + G), and placebo (P)
• Guaifenesin (p = 0.01) significantly inhibited cough reflex sensitivity relative to placebo
• B + G combination suppressed capsaicin-induced cough significantly more than B (p < 0.001) or G (p = 0.008) alone
Bennett (2010) To determine whether guaifenesin improves MCC in the healthy lung by assessing the rate of removal of inhaled radioactive tracer particles Open-label randomized crossover study (n = 8):
Single dose of 1200 mg guaifenesin vs placebo over 3 weeks; minimum 7-day washout period
Strong trend toward statistical significance (p = 0.07) for enhanced small airway clearance with guaifenesin vs placebo
Bennett (2015) To determine the effect of guaifenesin on MCC and cough clearance in non-smoking adults with acute URTI by assessing the rate of removal of inhaled radioactive tracer particles Randomized double-blind crossover study:
Single dose of 1200 mg guaifenesin vs placebo
No significant effect of single dose guaifenesin on mucociliary and cough clearance compared to placebo