<prompt> Dopamine is preferred over dobutamine in treatment of shock with oliguria because:-It has additional renal vasodilatory effectIt increases cardiac outputIt causes peripheral vasoconstriction onlyIt has prolonged action  <response>: Dopamine is the drug of choice for cardiogenic shock with oliguric renal failure. It acts on D1 at a dose of 1-2 mgkg min., b1 at 2-10 mgkgmin. and a1 at 10 mgkgmin. receptors. It causes renal vasodilation by acting on D1 receptors and maintains renal perfusion and GFR. Other ionotropic agents like NA cause renal vasoconstriction and thus worsen renal failure. 