Which of the following is not a sympathetic amine used for acute renal failure therapy?

The medication diltiazem is primarily classified as a calcium channel blocker and is not considered a sympathetic amine. Unlike sympathetic amines, which typically act on adrenergic receptors to enhance blood flow or improve kidney function during acute renal failure, diltiazem functions by inhibiting calcium influx into vascular smooth muscle and cardiac cells. This leads to vasodilation and can lower heart rate, but does not operate in the same pharmacological realm as the other drugs listed.

Dopamine, denopamine, and dopexamine, on the other hand, are indeed sympathetic amines used in the context of acute renal failure therapy. They work by stimulating adrenergic receptors in a way that can promote renal perfusion and improve urine output, thus making them more appropriate therapeutic agents for this condition. Understanding the specific roles and classifications of these drugs is crucial in managing renal failure effectively.