Guanoctine was studied as an antihypertensive agent.

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.

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.

Cariporide is a selective sodium-hydrogen antiporter inhibitor patented by a pharmaceutical company Hoechst A.-G. for treatment myocardial ischemia-reperfusion injury. The sodium-hydrogen exchanger is an important player in the pathophysiology of myocardial ischemia-reperfusion injury. The accumulation of hydrogen ions in the myocyte cytosol; during ischemia creates a proton gradient that promotes the efflux of hydrogen ions in exchange for the influx of sodium ions. This sodium buildup can secondary activates the sodium-calcium exchanger to operate in the reverse mode, resulting in a net calcium accumulation in myocyte cytosol, which leads to dysfunction and cell death. By inhibiting sodium-hydrogen exchange, Cariporide can prevent the accumulation of calcium in the cytosol, therefore reduce the infarct size. In clinical trials, Cariporide shows a statistically significant decline in myocardial infarction but increases mortality. Due to the increase in mortality, cariporide did not pass clinical trials.

Guanacline was studied in the treatment of hypertension. However, information about the current use of this compound is not available.

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.