Iobenguane I-131 is a radioactive therapeutic agent. The drug contains radioactive isotope I-131, which decays by electron emission with a half-life of about 8 days. By the chemical structure, iobenguane is similar to the neurotransmitter norepinephrine and is subject to the same uptake and regulation pathways. After intravenous administration, iobenguane I-131 accumulates within pheochromocytoma and paraganglioma cells, and radiation from the radioactive decay causes cell death and tumor necrosis. Iobenguane I-131 was approved by the FDA for the treatment of adult and pediatric patients with iobenguane scan positive, unresectable, locally advanced or metastatic pheochromocytoma or paraganglioma who require systemic anticancer therapy. Iobenguane I-131 is investigated in clinical trials as a treatment of neuroblastoma, ganglioneuroblastoma and other tumors of neuroendocrinal origin.

Pinacidil is a clinically effective vasodilator used for the treatment of hypertension.

Guanabenz, an antihypertensive agent for oral administration-, is an aminoguanidine derivative, 2,'6-dichlorobenzylideneamina-guanidine acetate. It is white to an almost white powder having not more than a slight odor. Sparingly soluble in water and in 0.1 N hydrochloric acid; soluble in alcohol and in propylene glycol. Guanabenz is an orally active central alpha-2 adrenergic agonist. Its antihypertensive action appears to be mediated via stimulation of central alpha-adrenergic receptors, resulting in a decrease of sympathetic outflow from the brain at the bulbar level to the peripheral circulatory system. In clinical trials, guanabenz acetate, given orally to hypertensive patients, effectively controlled blood pressure without any significant effect on glomerular filtration rate, renal blood flow, body fluid volume or body weight. The Myelin Repair Foundation and the National Institutes of Health (National Institute of Neurological Disorders and Stroke) are developing guanabenz for the treatment of multiple sclerosis. Unlike the currently available treatment for multiple sclerosis that suppresses the immune system, guanabenz, an FDA approved the drug for the treatment of high blood pressure, has a potential to reduce the loss of myelin by protecting and repairing myelin-producing cells in the brain from damage. Phase I development is underway in the US.