has part has role independent continuant (S,S)-labetalol (R,S)-labetolol (S,R)-labetolol analgesic beta-adrenergic antagonist antihypertensive agent alpha-adrenergic antagonist organic molecular entity racemate diastereoisomeric mixture labetalol CHEBI:6343 A diastereoisomeric mixture of approximately equal amounts of all four possible stereoisomers ((<i>R</i>,<i>S</i>)-labetolol, (<i>S</i>,<i>R</i>)-labetolol, (<i>S</i>,<i>S</i>)-labetalol and (<i>R</i>,<i>R</i>)-labetalol). It is an adrenergic antagonist used to treat high blood pressure. sympatholytic agent (R,R)-labetalol