Inhibition of cough-reflex sensitivity by benzonatate and guaifenesin in acute viral cough

Abstract

Acute cough due to viral upper respiratory tract infection (URI) is the most common form of cough and accounts for tremendous expenditure on prescription and non-prescription cough products worldwide. However, few agents have been shown in properly conducted clinical trials to be effective for cough due to URI. The present study evaluated the effect of benzonatate 200mg (B), guaifenesin 600 mg (G), their combination (B+G), and placebo (P) on capsaicin-induced cough in 30 adult nonsmokers with acute URI. On 3 separate days within a 7-day period, 1h after ingesting randomly assigned study drug in a double-blind fashion, subjects underwent capsaicin cough challenge testing, which involved inhalation of incremental doubling concentrations of capsaicin until the concentration of capsaicin inducing 5 or more coughs (C(5)) was attained. Each subject received 3 of 4 possible study drugs. G (p=0.01) but not B (p=NS) inhibited cough-reflex sensitivity (log C(5)) relative to P. The combination of B+G suppressed capsaicin-induced cough to a greater degree than B alone (p<0.001) or G alone (p=0.008). The mechanism by which the combination of B+G causes a potentiation of antitussive effect remains to be elucidated. Our results suggest that B+G may be an effective therapy for acute cough due to the common cold (URI).

Ternary metal complexes of guaifenesin drug: Synthesis, spectroscopic characterization and in vitro anticancer activity of the metal complexes

“…New ternary metal chelates (GFS as primary ligand and 1,10-phenanthroline as secondary ligand) with some transition metal ions were prepared and characterized by using different analytical techniques such as elemental analysis, molar conductance IR, 1 Numbers as given in Table 1 sh = sharp, m = medium, br = broad, s = small, w = weak. Numbers as given in Table 1.…”

“…Electronic spectra were recorded at room temperature on a Shimadzu 3101pc spectrophotometer as solutions in ethanol. 1 were measured on the using Jenway 4010 conductivity meter. The thermogravimetric analyses (TG and DTG) of the solid complexes were carried out from room temperature to 800 o C using a Shimadzu TG-50H thermal analyzer.…”

“…The ease with which many metal complexes undergo ligand substitution and redox reactions is likely to mean that the active species are biotransformation products of the administered complex. Identification of these active species will lead to the more effective use of metal compounds as drugs [1,2].…”

Benzonatate Toxicity in a Teenager Resulting in Coma, Seizures, and Severe Metabolic Acidosis

“…Benzonatate, also known as 4-(butylamino) benzoic acid, is structurally related to tetracaine ( Figure) and the ester-linked class of local anesthetics. 4 This structural resemblance results in similarities in mechanism of action and toxicity between benzonatate and local anesthetic agents. After oral ingestion and systemic absorption via the gastrointestinal tract, benzonatate acts peripherally by directly anesthetizing the vagal stretch receptors in the respiratory passages, lungs, and pleura.…”

Chemistry of drug interactions: Characterization of charge-transfer complexes of Guaifenesin with various acceptors using spectroscopic and thermal methods

“…1), is a constituent of guaiac resin from the wood of Guajacum officinale [1]. It is a widely used expectorant drug, and usually is taken orally to assist the bringing up of phlegm from the airway in acute respiratory tract infections and can be used for treatment sinusitis, pharyngitis, and bronchitis [2][3][4][5][6].…”