Albuterol

Albuterol is a widely used bronchodilator. It is one of a series of compounds that were patented in 1972 by L. H. C. Lunts and co-inventors and assigned to Allen and Hanburys, a British pharmaceutical company that dated back to the early 18th century. (It eventually became part of the GlaxoSmithKline conglomerate.)

The patent describes the compounds of the invention as stimulants or blockers of β-adrenergic receptors. It is now known that albuterol is a short-acting β₂-adrenergic receptor agonist. It is prescribed for treating pulmonary conditions such as bronchitis, asthma, and chronic obstructive pulmonary disease.

Albuterol is a racemic mixture. The pharmaceutical literature contains conflicting accounts of the mechanisms of action of the two enantiomers. What is clear is that (R)-albuterol has 100–150 times greater affinity for β₂-receptors than the (S) enantiomer and is likely responsible for bronchodilation. In some accounts, (S)-albuterol is said to increase bronchial activity, but in others it is described as inactive.