3-adrenergic antagonists pindolol

Propranolol is the [3-adrenergic antagonist most widely used in the treatment of cardiac arrhythmias. However, Pi-specific drugs, such as metoprolol (see p. 77) reduce the risk of bronchospasm, and drugs with partial agonist activity, such as pindolol (see p. 77), may decrease the frequency of cardiac failure. 

P-adrenergic antagonists (ISA) pindolol, carteolol, penbutolol endothelin A antagonists LU135252, TBC 11251, PD 163070... 

The separation of pindolol enantiomers, a nonselective j8-adrenergic antagonist, by chemical derivatization with sugar-based derivatizing agent is reported [76]. 

Esmolol hydrochloride is a competitive p-adrenergic receptor antagonist it is selective for pT adrenoceptors. In contrast to pindolol, esmolol has little intrinsic sympathomimetic activity, and it differs from propranolol in that it lacks membrane stabilizing activity Of all of the p-adrenergic blocking drugs, this compound has the shortest duration of action because it is an ester, it is hydrolyzed rapidly by plasma esterases and must be used by the intravenous route Esmolol is approved only for the treatment of supraventricular arrhythmias... 

Pindolol is a partial agonist at the P2-adrenergic receptor, and has antagonistic actions at the P,-receptor. Thus, cardiac output is reduced with the drug, due to p,-receptor antagonism, and vasodilatation is increased, due to the effects of p2-receptor stimulation. 

Labetalol (normodyne, trandate) fsee Chapter 10) is a mixture of four stereoisomers. One isomer is an (Xj antagonist (like prazosin), another is a nonselective f) antagonist with partial agonist activity (like pindolol), and the other two isomers are inactive. Because of its capacity to block (Xj adrenergic receptors, intravenous labetalol can reduce pressure sufficiently rapidly to be useful for the treatment of hypertensive emergencies. Labetalol has efficacy and side effects that would be expected with any combination of f) and (Xj receptor antagonists as with any fixed-dose combination, the relative extents of (X receptor and receptor antagonism vary from patient to patient. 

Agonists isoproterenol > epinephrine > norepinephrine Antagonists ICl 118,551 > betaxolol Pi-adrenergic receptors Agonists pindolol Antagonists BRL 37344... 

---