The effects of oral almitrine on pattern of breathing and gas exchange in patients with chronic obstructive pulmonary disease.
Stradling JR., Nicholl CG., Cover D., Davies EE., Hughes JM., Pride NB.
Almitrine at a low dose of 100 mg orally significantly raises PaO2 and lowers PaCO2 in patients with chronic obstructive pulmonary disease, compared with placebo, when they were breathing air or 28% oxygen. The estimated ideal alveolar-arterial PO2 difference was less after almitrine compared with placebo, when patients were breathing either air or 28% oxygen. After almitrine overall ventilation breathing air increased by 10% but this did not reach statistical significance. During 28% oxygen breathing almitrine hardly altered overall ventilation but the inspiratory duty cycle (Ti/Ttot.) decreased and mean inspiratory flow rate (VT/Ti) increased compared with placebo. These changes were significant on a paired t-test (P less than 0.05). Changes in both volume and pattern of breathing may explain the improved gas exchange in the lung after almitrine.