Iobenguane Sulfate I-123

**Semantic type:** Pharmacologic Substance

**Definition:** The sulfate salt form of iobenguane, an iodine-123 labeled aralkylguanidine norepinephrine analogue used as a diagnostic imaging tracer. Iobenguane is structurally related to guanethidine and norepinephrine. This agent, functioning as a false substrate of norepinephrine, is taken up and localized in the granules of pre-synaptic adrenergic neurons, thus making this compound useful for the imaging of neuroendocrine tissues and tumors.