title: Pattern of breathing and gas exchange following oral almitrine bismesylate in patients with chronic obstructive pulmonary disease.
abstract: Almitrine bismesylate (100 mg orally) significantly raised PaO2 and lowered PaCO2 in six patients with chronic obstructive pulmonary disease, compared to placebo, when they were breathing air or 28% oxygen. The estimated ideal alveolar arterial PO2 difference (AaDO2) was less after almitrine bismesylate compared to placebo, when patients were breathing either air or 28% oxygen. After almitrine bismesylate overall ventilation breathing air increased by 10% but this did not reach statistical significance. During 28% oxygen breathing, almitrine bismesylate hardly altered overall ventilation but the inspiratory duty cycle (TI/TTOT) decreased and mean inspiratory flow rate (VT/TI) increased compared to placebo. These changes were significant on a paired T test (P less than 0.05). The improvement in AaDO2 correlated with the rise in VT/TI (r = 0.67, P = 0.02) and thus we suggest that changes in both volume and pattern of breathing might explain the improved gas exchange in the lung after almitrine bismesylate .
mesh_terms: D000284:Administration, Oral; D000368:Aged; D015765:Almitrine; D002986:Clinical Trials as Topic; D005260:Female; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D010879:Piperazines / Q000627:therapeutic use*; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D012119:Respiration / Q000187:drug effects*; D014692:Ventilation-Perfusion Ratio / Q000187:drug effects
chemical_list: D010879:Piperazines; D015765:Almitrine