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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We wished to determine whether ibopamine, a dopaminergic prodrug with weak agonist activity on alpha- and beta-adrenoceptors, improves orthostatic tolerance in autonomic insufficiency. Three subjects with severe orthostatic hypotension resulting from pure autonomic failure (PAF) were studied. Direct arterial blood pressure (ABP) and heart rate (HR) were recorded continuously. Orthostatic tolerance was evaluated by 60 degrees passive head-up tilting. Tilting was performed before and after a single oral 100-mg dose of ibopamine. Blood samples for measurement of plasma catecholamines, free epinine (the active metabolite of ibopamine), and conjugated epinine were taken at regular intervals. In all 3 subjects, orthostatic tolerance was greatly improved by ibopamine. This improvement occurred as soon as 10-30 min after administration of ibopamine and lasted 20-50 min. alpha-Adrenoceptor blockade with phentolamine abolished the effect of ibopamine. The interindividual pharmacokinetics of ibopamine varied considerably: Peak plasma concentrations of ibopamine in the three subjects were 2.8, 4.5, and 35.4 ng/ml, respectively. The high level of epinine in one patient was associated with severe hypertension and tachycardia. Ibopamine may be a valuable new pharmacologic treatment for orthostatic hypotension in PAF, but in light of the highly variable interindividual pharmacokinetics further studies must be performed before use of the compound can be advocated in this disorder.
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PMID:Effects of ibopamine on postural hypotension in pure autonomic failure. 768 9

Dopamine and a new group of selective and nonselective peripheral dopaminergic receptor effectors are being evaluated for the treatment of various cardiovascular disorders, including shock, CHF, and systemic hypertension. Dopamine, in relatively low intravenous doses, will stimulate both peripheral DA1 receptors, which mediate arterial vasodilation of different vascular beds, and the DA2 receptors, which mediate the inhibition of norepinephrine release. Ibopamine is a new oral, nonspecific peripheral dopaminergic agonist with an active metabolite (epinine) that is being evaluated in patients with CHF. Fenoldopam is a selective peripheral DA1 agonist now being developed as a parenteral treatment for hypertensive emergencies. Dopexamine is a parenteral agent that selectively activates both DA1 and beta 2 adrenergic receptors and is being evaluated in patients with CHF and in individuals with postoperative left ventricular dysfunction. A group of selective DA2 receptor agonists is being evaluated as long-term treatment for systemic hypertension.
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PMID:Selective and nonselective dopamine receptor agonists: an innovative approach to cardiovascular disease treatment. 883 78

In the periphery, physiological dopamine increases renal blood flow, decreases renal resistance and acts on the kidney tubule to enhance natriuresis and diuresis. The loss of dopamine function may be involoved in the deterioration in kidney function associated with ageing and may have a role in the pathogenesis of hypertension and diabetes. Intravenous dopamine is used as a positive inotrope in the treatment of acute heart failure and cardiogenic shock and as a diuretic in renal failure. The clinical uses of dopamine are limited, as it must be given intravenously, and also has widespread effects. The levels of peripheral dopamine can be increased by the administration of L-dopa to increase synthesis, prodrugs to release dopamine (docarpamine, glu-dopa) or by inhibiting the breakdown of dopamine (nitecapone). Preliminary clinical trials suggest that docarpamine may be useful in patients with low cardiac output syndrome after cardiac surgery and in refractory cirrhotic ascites. Ibopamine is an agonist at dopamine D1 and D2 receptors, which may retard the progression of chronic renal failure. Glu-dopa is selective for the kidney, thus avoiding widespread side effects. The early clinical studies with ibopamine as a diuretic in heart failure were favourable but the subsequent large mortality study showed that ibopamine increased mortality. Fenoldopam is a selective dopamine D1 receptor agonist. Intravenous fenoldopam may be useful in the treatment of hypertension associated with coronary artery bypass surgery or in hypertensive emergencies. Although our understanding of physiological and pathological roles of peripheral dopamine has been increasing rapidly in recent times, we still need more information to allow the design of clinically useful drugs that modify these roles. One priority is an orally-active selective dopamine D1 receptor agonist.
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PMID:The therapeutic potential of dopamine modulators on the cardiovascular and renal systems. 1199 45