Pirbuterol

Clinical data
Trade names	Maxair
AHFS/Drugs.com	Consumer Drug Information
MedlinePlus	a601096
Pregnancy category	C
Routes of administration	Inhalational (MDI)
ATC code	R03AC08 (WHO) R03CC07 (WHO)
Legal status
Legal status	AU: S4 (Prescription only) US: ℞-only
Identifiers
IUPAC name (RS)-6-[2-(tert-butylamino)-1-hydroxyethyl]-2-(hydroxymethyl)pyridin-3-ol
CAS Number	38677-81-5 Y HCl: 38029-10-6 Y
PubChem CID	4845
IUPHAR/BPS	7272
DrugBank	DB01291 Y
ChemSpider	4679 Y
UNII	OG645J8RVW HCl: J6793T658K Y
KEGG	D08387 N
ChEMBL	ChEMBL1094966 Y
CompTox Dashboard (EPA)	DTXSID0046937
Chemical and physical data
Formula	C12H20N2O3
Molar mass	240.303 g·mol−1
3D model (JSmol)	Interactive image
Chirality	Racemic mixture
SMILES Oc1ccc(nc1CO)C(O)CNC(C)(C)C
InChI InChI=1S/C12H20N2O3/c1-12(2,3)13-6-11(17)8-4-5-10(16)9(7-15)14-8/h4-5,11,13,15-17H,6-7H2,1-3H3 Y Key:VQDBNKDJNJQRDG-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

Pirbuterol (trade name Maxair) is a short-acting β₂ adrenoreceptor agonist with bronchodilating action used in the treatment of asthma, available (as pirbuterol acetate) as a breath-activated metered-dose inhaler.

It was patented in 1971 and came into medical use in 1983.^[1]

Medical use

Pirbuterol is used in asthma for reversal of acute bronchospasm, and also as a maintenance medication to prevent future attacks. It should be used in patients 12 years of age and older with or without concurrent theophylline and/or inhaled corticosteroid.^[2][3]

Mode of action

Pharmacokinetics

After inhalation of doses up to 800 μg (twice the maximum recommended dose) systemic blood levels of pirbuterol are below the limit of assay sensitivity (2–5 ng/ml). A mean of 51% of the dose is recovered in urine as pirbuterol plus its sulfate conjugate following administration by aerosol. Pirbuterol is not metabolized by catechol-O-methyltransferase. The plasma half-life measured after oral administration is about two hours.^[2]

Adverse effects