IOBENGUANE I-123 (AdreView®) is a radiopharmaceutical agent for gamma-scintigraphy. It is similar in structure to the antihypertensive drug guanethidine and to the neurotransmitter norepinephrine (NE). IOBENGUANE is, therefore, largely subject to the same uptake and accumulation pathways as NE. It is taken up by the NE transporter in adrenergic nerve terminals and stored in the presynaptic storage vesicles. IOBENGUANE accumulates in adrenergically innervated tissues such as the adrenal medulla, salivary glands, heart, liver, spleen, and lungs as well as tumors derived from the neural crest. By labeling IOBENGUANE with the isotope iodine 123 (I-123), it is possible to obtain scintigraphic images of the organs and tissues in which the radiopharmaceutical accumulates. IOBENGUANE I-123 (AdreView®) is indicated for use in the detection of primary or metastatic pheochromocytoma or neuroblastoma. It is also used for scintigraphic assessment of sympathetic innervation of the myocardium by measurement of the heart to mediastinum (H/M) ratio of radioactivity uptake in patients with New York Heart Association (NYHA) class II or class III heart failure and left ventricular ejection fraction (LVEF) ≤ 35%. Among these patients, IOBENGUANE I-123 (AdreView®) may be used to help identify patients with lower one and two-year mortality risks, as indicated by an H/M ratio ≥ 1.6.

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.

Cimetidine is a histamine H2-receptor antagonist. It reduces basal and nocturnal gastric acid secretion and a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli including food, caffeine, insulin, betazole, or pentagastrin. It is used to treat gastrointestinal disorders such as gastric or duodenal ulcer, gastroesophageal reflux disease, and pathological hypersecretory conditions. Cimetidine inhibits many of the isoenzymes of the hepatic CYP450 enzyme system. Other actions of Cimetidine include an increase in gastric bacterial flora such as nitrate-reducing organisms. Cimetidine binds to an H2-receptor located on the basolateral membrane of the gastric parietal cell, blocking histamine effects. This competitive inhibition results in reduced gastric acid secretion and a reduction in gastric volume and acidity.

Meobentine is an antiarrhythmic agent. Meobentine significantly increases the electrical ventricular fibrillation threshold in animal models. Meobentine may prevent induction of ventricular tachycardia or fibrillation, or reduce frequency of complex ventricular ectopy in selected patients refractory to other antiarrhythmic agents, but the response rate is relatively low.

Etintidine is a potent competitive antagonist of histamine H2-receptors. It has a low level of antiandrogenic activity. Etintidine was being investigated in the treatment of peptic ulcer, however, its development has been discontinued.

Guanoxyfen sulfate is an antidepressant, antihypertensive. Guanoxyfen sulfate is an inhibitor of vasoconstrictor responses to sympathetic nerve stimulation. It could potentiate the actions of adrenaline and noradrenaline. It also could increase the blood glucose concentration and decrease the appetite.

Impromidine is a highly potent and specific histamine H2 receptor agonist used diagnostically as a gastric secretion indicator. The value of impromidine as an effective acid-secretory stimulant is limited by its tendency to cause cardiovascular side-effects, that mediated by H2-receptors in the cardiovascular system.

Naminidil, a potassium channel opener, was under development with Bristol-Myers Squibb as a topical treatment for androgenetic alopecia. The research has been discontinued.

Sephin1 is a guanabenz derivative that binds to and inhibits a regulatory subunit of the stress-induced protein phosphatase 1 (PPP1R15A), but not the constitutive PPP1R15B, and lacks beta2-adrenergic activity. Phosphorylation of eIF2α, α subunit of eukaryotic translation initiation factor 2, reduces protein synthesis and prevents the accumulation of misfolded protein in the endoplasmic reticulum (ER). PPP1R15A recruits the serine/threonine-protein phosphatase PP1 to dephosphorylate eIF2α, so inhibiting PPP1R15A activity prolongs the phosphorylation of eIF2α and aids in its prevention of the accumulation of misfolded protein. In vitro, Sephin1 protected cells from lethal protein misfolding and cytotoxic ER stress. In vivo Sephin1 prevented Charcot-Marie-Tooth 1B and ALS diseases in mice.