Congestive heart failure agonists

J Antagonist Partial agonist Asthma, hypertension, congestive heart failure... 

Dopamine itself has long been used as an inotropic agent in acute treatment of congestive heart failure. Both that compound and a number of its analogues have a positive action on contractility as a consequence of their adrenergic agonist activity. 

Dopamine and dobutamine are sometimes used to stimulate the heart in cases of acute or severe heart failure (see Chapter 20). Dopamine and dobutamine exert a fairly specific positive inotropic effect, presumably through their ability to stimulate beta-1 receptors on the myocardium.60 Other beta-1 agonists (epinephrine, prenalterol, etc.) will also increase myocardial contractility, but most of these other beta-1 agonists will also increase heart rate or have other side effects that prevent their use in congestive heart failure. Dopamine and dobutamine are usually reserved for patients with advanced cases of congestive heart failure who do not respond to other positive inotropic drugs (e.g., digitalis).6,72... 

Partial agonists, such as acebutolol, oxprenolol, pindolol, practolol, and xamoterol, produce less resting bradycardia. It has also been claimed that such agents cause a smaller increase in airways resistance in asthmatics, less reduction in cardiac output (and consequently a lower risk of congestive heart failure), and fewer adverse effects in patients with cold hands, Raynaud s phenomenon, or intermittent claudication. However, none of these advantages has been convincingly demonstrated in practice, and patients with bronchial asthma or incipient heart failure must be considered at risk with this type of compound. 

Congestive heart failure P-Agonists Acute inotropic support Dobutamine, Orciprenaline... 

The discovery of the selective vasodilation produced by dopamine in the renal circulation and of its natriuretic effects, both mediated by D receptors, respectively in renal arteries and in renal tubules, prompted research of new D selective and peripherally acting agonists, potentially useful in the treatment of congestive heart failure and of hypertension. In the most severe forms of the former clinical condition, dopamine is used by intravenous infiision, taking... 

Peripheral dopaminergic receptor agents are useful in the treatment of congestive heart failure (CHF). Two distinct subtypes of dopamine receptors have been identified. The dopamine (DAi) receptors, which are located on vascular smooth muscles, cause vasodilation in the renal, mesentery, cerebral, and coronary vascular beds (see Figure 49). Thus, the pharmacologic response to activation of the DA2- and DAj-receptor receptors is hypotension, bradycardia, diuresis, and natriuresis. Fenoldopam is an orally active DA -receptor agonist. It is more potent than dopamine in causing... 

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