The β-adrenergic receptor antagonists all have similar therapeutic and pharmacodynamic actions in patients with cardiovascular disorders. They vary greatly in their pharmacokinetic properties, as they demonstrate a high range of values in plasma protein binding, the percent of drug eliminated by metabolism or unchanged in the urine and hepatic extraction ratio.  Each of the β-blockers possesses at least one chiral centre and a high degree of enantioselectivity when binding to the β-adrenergic receptor. For those β-blockers containing a single chiral centre, the (-) enantiomer has a much higher affinity in binding to the β-adrenergic receptor than the (+) enantiomer. All β-blockers used systemically are delivered as racemate, except for timolol.