dextromethorphan and Dyspnea

The efficacy of an antitussive-beta 2-sympathomimetic combination (dextromethorphan-salbutamol) was compared with that of a plain antitussive (dextromethorphan) and a placebo in a double-blind trial in 108 out-patients with cough associated with acute respiratory infection. The dextromethorphan-salbutamol combination was superior to dextromethorphan or placebo in the suppression of cough at night, although a spontaneous improvement occurred in all treatment groups during the 4-day treatment period. No statistically significant differences between the treatments were shown in the symptom scores for the cough frequency and severity during the day, sputum quantity or ease of expectoration. A significant improvement in cough during the day was observed in all treatment groups. The results suggest that the use of antitussives is usually unnecessary; the only indication might be symptomatic relief, especially at night. An antitussive combined with a beta 2-sympathomimetic might be the most effective treatment in this type of cough.

Topics: Acute Disease; Adult; Albuterol; Cough; Dextromethorphan; Double-Blind Method; Drug Combinations; Dyspnea; Female; Humans; Levorphanol; Male; Random Allocation

We have previously shown that the exercise performance of patients with severe chronic obstructive pulmonary disease (COPD) can be increased with the administration of oral morphine (0.8 mg.kg-1). The purpose of this study was to determine whether the administration of dextromethorphan (DXT), an antitussive structurally similar to codeine, would result in increased exercise performance and decreased dyspnoea in patients with COPD, without the side-effects of opiates. Six eucapnic patients (mean age = 66 +/- 3.8 yrs) with COPD (mean forced expiratory volume in one second (FEV1) = 1.01 +/- 0.07 l) underwent two incremental cycle ergometer tests to exhaustion (Emax) and assessment of their hypercapnic and hypoxic ventilatory responses and mouth occlusion pressure responses following first the oral administration of placebo (P) and then dextromethorphan (60 mg) in a single-blind fashion. There was no statistically significant difference in the maximal exercise performance, perceived dyspnoea (modified Borg scale), breathing pattern or expired gases after the two different treatments. In addition, the ventilatory response to CO2 production during exercise (delta VE/VCO2) and the ventilatory and mouth occlusion pressure responses to hypoxia and hypercapnia did not differ significantly after DXT as compared with after P. Indeed the exercise performance was poorer and the ventilatory responses were brisker after DXT. We conclude from this study that the administration of this opiate analogue does not improve the exercise capacity or decrease the ventilatory response of patients with COPD.

Topics: Aged; Carbon Dioxide; Dextromethorphan; Dyspnea; Exercise Test; Humans; Lung Diseases, Obstructive; Middle Aged; Oxygen; Oxygen Consumption; Respiratory Mechanics; Single-Blind Method