Name: Dopamine
Class: CHF Rx (b-Adrenergic Agonist)
Mechanism: ¯ dose ® D1 stim. dose ® b1 stim. Also releases NE from symp. neur. Causes vasodilation in renal, mesenteric, and coronary beds ® renal blood flow, glomerular filtration, and Na+ excretion. Also causes ¯ Na+ and H20 resorption. High doses ® HR. Usu. increases systolic BP and pulse pressure. Low-mod. doses ® static or decreased vasc. resistance. High conc. ® a1 activation ® vasoconstriction ® BP. cAMP ® contractility.
Absorption: No oral. IV. Onset w/in 5 min.
Dist.:
Metabolism.: Catab. by COMT and MAO, esp. in liver and kidneys. Glucuronidation and sulfconjugation
Excretion, t½: Duration of action 10 min. t½: 2 min.
Toxicity/S.E.s: Nausea, vomiting, tachycardia, anginal pain, arrhythmia, headache, hypertension, vasoconstriction. Usu. due to excessive symp activity. Treat by stopping admin. or w/a blockers. Local ischemic necrosis. Contraind. w/pheochromocytomas, uncorrected tachyarrhythm. or vent. fibrillation, MAO inhibitors, furazolidone. Adjust dose w/tricyclics.
Utility: Some shock (e.g., oliguria and low-normal periph. resist, cardiogenic/septic shock). CHF.