Inhibition of cough reflex sensitivity by diphenhydramine during acute viral respiratory tract infection.

Background: Currently available over-the-counter cough remedies historically have been criticized for lack of scientific evidence supporting their efficacy. Although the first-generation antihistamine diphenhydramine is classified as an antitussive by the United States Food and Drug Administration, to the authors' knowledge it has never been shown to inhibit cough reflex sensitivity in subjects with pathological cough.

Objective: To evaluate the effect of diphenhydramine on cough reflex sensitivity.

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

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.

Lack of effect of L-carnitine supplementation on weight gain in very preterm infants.

Objective: Carnitine transfer across the placenta occurs predominantly during the third trimester. Unless L-carnitine is provided, very preterm infants develop carnitine deficiency. Although breast milk and infant formulas contain L-carnitine, parenteral nutrition solutions do not routinely provide L-carnitine.

Effect of guaifenesin on cough reflex sensitivity.

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.

Effect of the second-generation antihistamine, fexofenadine, on cough reflex sensitivity and pulmonary function.

Aims: Current guidelines recommend the use of first-generation antihistamines for the treatment of cough due to rhinitis/postnasal drip syndrome. The antitussive activity of the second-generation antihistamine, fexofenadine, has not been investigated. Therefore, we evaluated the effect of fexofenadine on capsaicin-induced cough in healthy volunteers and in subjects with acute viral upper respiratory tract infection (URI).