Systematic (IUPAC) name
Clinical data
AHFS/Drugs.com monograph
MedlinePlus a682084
Pregnancy cat. A(AU) C(US)
Legal status -only (US)
Routes Inhalation / tablets
Pharmacokinetic data
Bioavailability 3% if inhaled, 40% if taken orally
Metabolism Gastrointestinal and hepatic
Half-life 6 hours
CAS number 586-06-1 YesY
ATC code R03AB03 R03CB03
PubChem CID 4086
DrugBank DB00816
ChemSpider 3944 YesY
UNII 53QOG569E0 YesY
KEGG D08300 YesY
Chemical data
Formula C11H17NO3 
Mol. mass 211.258 g/mol
SMILES eMolecules & PubChem
Physical data
Solubility in water 9.7 mg/mL (20 °C)
 N(what is this?)  (verify)

Orciprenaline (INN, also known as metaproterenol) is a bronchodilator used in the treatment of asthma. Orciprenaline is a moderately selective beta2-adrenergic receptor agonist that stimulates receptors of the smooth muscle in the lungs, uterus, and vasculature supplying skeletal muscle, with minimal or no effect on alpha-adrenergic receptors. The pharmacologic effects of beta adrenergic agonist drugs, such as orciprenaline, are at least in part attributable to stimulation through beta adrenergic receptors of intracellular adenyl cyclase, the enzyme which catalyzes the conversion of ATP to cAMP. Increased cAMP levels are associated with relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from many cells, especially from mast cells.