Effect of almitrine bismesylate on pulmonary vasoreactivity to hypoxia in chronic obstructive pulmonary disease

Abstract

The aim of this double-blind, placebo-controlled study was to determine whether acute administration of almitrine enhances hypoxic pulmonary vasoconstriction in patients with chronic obstructive pulmonary disease (COPD). Haemodynamics and blood gases were studied at various inspiratory fractional concentrations of oxygen (FIO2): 0.15, 0.21, 0.30 and 1.0, randomly administered for 20 min periods under constant infusion of either placebo or almitrine (8 micrograms.kg-1.min-1) in 20 patients with COPD. The almitrine group exhibited a significant increase in mean pulmonary artery pressure, pulmonary vascular resistance and arterial oxygen tension (PaO2) at FIO2 0.15, 0.21 and 0.30. During hypoxia, the increase in mean pulmonary pressure and pulmonary vascular resistance was three times greater in the almitrine group than the placebo group. No significant difference in cardiac output and systemic haemodynamics was found. These results suggest that almitrine at the dose used, enhances pulmonary vasoconstriction in COPD patients.

Dose-dependent effects of almitrine on hemodynamics and gas exchange in an animal model of acute lung injury

“…With regard to measuring purposes, there is a reproducible, steady-state condition after 30 min of each dose, as reported by Naeije and coworkers [40]. This was confirmed by Saadjian and coworkers [29]. Starting out from the assumption that accumulation would take place, we chose an infusion setting providing that the whole spectrum of doses can be applied.…”

“…Therefore, the observed differences in dose-response cannot be explained on a molecular basis, as yet. However, the effects of almitrine on pulmonary circulation may not only be dose-dependent but may also be influenced by the reactivity of the pulmonary vessels to hypoxia [29].…”