Almitrine effect on nocturnal hypoxaemia in patients with chronic obstructive pulmonary disease (COPD)

Almitrine bismesylate (A) is a peripheral chemoreceptor agonist that increases ventilation, improves V/Q matching, increases PaO2 and decreases PaCO2 in patients with COPD. We have used a placebo-controlled double-blind cross-over study to compare the effect of 1.5 mg.kg-1 A and placebo (P) (given orally twice a day for 14 days with a 2 wk wash-out period between) on sleep quality, blood oxygenation during sleep and the ventilatory response to hypoxia and hypercapnia when awake. We have measured ear oxygen saturation (SaO2) and EEG sleep stages during nocturnal sleep in 13 patients with COPD (FEV1 0.94 +/- 0.31 1). When awake and during P period PaO2 was 51.4 +/- 10.7 mmHg (SD), PaCO2 53.1 +/- 7.1 mmHg and SaO2: 83.1 +/- 8.0%: during A treatment PaO2 increased to 55.8 +/- 7.8 mmHg (p less than 0.01 paired Wilcoxon test), PaCO2 decreased to 48.5 +/- 6.4 mmHg (p less than 0.05) and SaO2 increased to 86.9 +/- 2.6 (p less than 0.01). A reduced nocturnal hypoxaemia: 1) during P treatment mean stage I SaO2 was 73.2 +/- 13.2%, stage II 70.5 +/- 15.7%, stage III 66.5 +/- 18.5%, stage IV 73.3 +/- 12.7% and rapid eye movement (REM) sleep 59.2 +/- 14.8%; the corresponding SaO2 values during A treatment were higher: stage I SaO2 80.6 +/- 5.2% (p less than 0.05), II 78.6 +/- 6.2% (p less than 0.01), III 77.3 +/- 7.4% (p less than 0.01), IV 80.4 +/- 3.8% (p less than 0.05), REM 69.9 +/- 7.9% (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)