Pindolol Epinephrine

Pindolol is a partial P-receptor agonist. It has weak agonist activity, particularly at the P2 receptor, but acts as an antagonist in the presence of norepinephrine or epinephrine (see Figure below). It may thus be used in the therapy of inappropriate norepinephrine secretion. Due to its ability to weakly stimulate the P2 receptor while blocking the Pj receptor, it is also useful in the therapy of hypertension. 

Describe the effects of an alpha-blocker on the hemodynamic responses to epinephrine. Describe the effects of an alpha-blocker on the hemodynamic responses to norepinephrine. Compare the effects of propranolol, labetalol, metoprolol, and pindolol. 

Sugimura M, Hirota Y, Shibulani T, Niwa H, Hori T, Kim Y, Matsuura H. An echocardio-gr hic sbufy of interactions between pindolol and epinephrine contained in a local anesthetic solution Anes t Prog (1995) 42,29-35. 

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

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