Acetylcysteine: a drug that is much more than a mucokinetic.

Acetylcysteine is the most widely used mucolytic drug, and it has greater documentation of effectiveness than any other mucokinetic agent. Originally it was used as an aerosol, but currently it is mostly prescribed by the oral route. In addition to the lytic activities of acetylcysteine, the aerosolized drug has bronchorrheic effects, while oral therapy results in expectorant and mucoregulator actions. Newer uses of the drug depend on its effectiveness as a free-radical scavenger, since it is a precursor of glutathione. It is well established as the drug of choice for treating acetaminophen poisoning, and it offers an important role in protecting the lungs from a variety of insults that result in oxidant damage.