Incubation with Oxitropium bromide of the untreated diaphragm muscle and diaphragm muscle injected with endotoxin does not increase the force-frequency curves dose-dependently in vitro; but, it induces both types of muscle to be fatigue resistant. Oxitropium bromide is a muscarinic antagonist that blocks musucarinic acetylcholine receptors (mAChR) [1].

Oxitropium bromide strongly and persistently inhibits the acetylcholine (ACh)-induced resistance. The increase in resistance induced by histamine, serotonin, leukotriene D4, or antigen is prevented by Oxitropium bromide Oxitropium bromide. Oxitropium bromide inhalation shifts force-frequency curves upward at 2 h after inhalation and inhibits the decrease of force-frequency curves due to endotoxin injection in vivo. Inhalation of the anticholinergic agent Oxitropium bromide at doses of 1.5 μg and higher greatly attenuates the decrease in mucus score produced by intravenous histamine but not by inhaled histamine [1][2][3].