THE EFFECT OF INTRAVENOUSLY ADMINISTERED ALMITRINE, A PERIPHERAL CHEMORECEPTOR AGONIST, ON PATIENTS WITH CHRONIC AIR-FLOW OBSTRUCTION

Abstract

Almitrine, a peripheral chemoreceptor agonist, was given i.v. in a dose of 0.5 mg/kg per h for 2 h in a randomized double-blind manner with placebo, to 11 patients with severe chronic air-flow obstruction and hypoxemia (SaO2 [arterial O2 saturation] < 90%). There was no significant placebo effect. Maximal respiratory effect occurred at the end of the almitrine infusion with an increase in ventilation from 8.2 + 0.9 to 11.6 + 1.5 l/min (mean .+-. SEM [standard error of the mean]), and improvements in SaO2 from 83 .+-. 3 to 90 .+-. 2%, in PaO2 [arterial partial pressure of O2] from 48 .+-. 2 to 55 .+-. 3 mm Hg in PaCO2 from 54 + 3 to 47 .+-. 4 mm Hg. Venous admixture was reduced from 38 .+-. 4 to 22 .+-. 3%. In 4 patients, blood gas values substantially improved, but there was no change in total ventilation or ventilatory pattern. This study of acute effects showed that almitrine improved arterial PO2 and PCO2 in patients with chronic air-flow obstruction both by increasing ventilation and by improving ventilation-perfusion relationships.