Arformoterol

Absorption	Not Available
Volume of distribution	Not Available
Protein binding	The binding of arformoterol to human plasma proteins in vitro was 52-65% at concentrations of 0.25, 0.5 and 1.0 ng/mL of radiolabeled arformoterol.
Metabolism	Arformoterol was almost entirely metabolized following oral administration of 35 mcg of radiolabeled arformoterol in eight healthy subjects. Direct conjugation of arformoterol with glucuronic acid was the major metabolic pathway. O-Desmethylation is a secondary route catalyzed by the CYP enzymes CYP2D6 and CYP2C19. Enzyme Metabolite Reaction Km Vmax Cytochrome P450 2D6 O-demethylation Cytochrome P450 2C9 O-demethylation Cytochrome P450 2A6 O-demethylation Cytochrome P450 2C19 O-demethylation
Route of elimination	After administration of a single oral dose of radiolabeled arformoterol to eight healthy male subjects, 63% of the total radioactive dose was recovered in urine and 11% in feces within 48 hours. Direct glucuronidation of arformoterol is mediated by several UGT enzymes and is the primary elimination route.
Half life	In COPD patients given 15 mcg inhaled arformoterol twice a day for 14 days, the mean terminal half-life of arformoterol was 26 hours.
Clearance	renal cl=8.9 L/hr [Healthy male subjects]
Toxicity	A death was reported in dogs after a single oral dose of 5 mg/kg (approximately 4500 times the maximum recommended daily inhalation dose in adults on a mg/m2 basis). As with all inhaled sympathomimetic medications, cardiac arrest and even death may be associated with an overdose.
Affected organisms	Humans and other mammals