Carprazidil is oxadiazolopyrimidine derivative patented by pharmaceutical company Hoffmann-La Roche as a direct vasodilator and potent antihypertensive agent. In clinical trials, Carprazidil was evaluated in patients with moderate to severe arterial hypertension. Following the addition of Carprazidil to pre-existing therapy with diuretics and beta-blockers or sympatholytics, blood pressure in most of the patients was normalized within one month. Heart rate was only slightly increased. Orthostatic hypotension was not observed. Weight gain or oedema formation occurred in 14 patients within the first four weeks, but could be controlled satisfactorily by intensified diuretic therapy. After a mean duration of treatment of 2.8 months, plasma volume and plasma and urine sodium were unaltered, and plasma potassium was slightly decreased. Plasma renin activity was doubled, whereas plasma aldosterone concentrations were unaltered. No adverse side effects on hematological parameters, liver or renal function were observed, nor was antinuclear antibody detected.

Manozodil is a vasodilator agent.

Mepramidil (PF-26) is a coronary vasodilator.

FENETRADIL is a coronary dilator.

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.

Bumepidil (also known as CS-611) is intravenously administered coronary vasodilator with antiarrhythmic action. In anesthetized, open-chest dogs Bumepidil in doses of 0.1--1 mg/kg i.v. decreased systemic blood pressure, coronary resistance and arterio-venous oxygen difference and increased coronary sinus outflow in a dose-related manner, but myocardial oxygen consumption was virtually unchanged. At 0.3 mg/kg i.v. of the drug, coronary sinus outflow was doubled, but heart rate and AV conduction time were not changed. Bumepidil shortened the action potential duration (APD) of each tissue, especially of Purkinje fibers, without any significant alterations in the resting membrane potential, action potential amplitude and maximum rate of rising. Bumepidil can be characterized as a coronary dilator virtually devoid of cardiac actions in doses sufficiently increasing coronary blood flow.

Racemetirosine is an orally active inhibitor of the enzyme tyrosine 3-monooxygenase, and consequently of the synthesis of catecholamine. At dosages of 600 to 3500mg daily, it is effective in controlling the hypertensive episodes and symptoms of catecholamine excess in phaeochromocytoma during preparation for surgery. Oral Racemetirosine is well absorbed and absorption appears constant in each individual over a wide dosage range. The drug is largely excreted via the kidneys, but extrarenal elimination has not been studied. Case reports on the clinical use of Racemetirosine in phaeochromocytoma indicate that the drug controls hypertension and symptoms of catecholamine excess in most patients during preparation for surgical removal of a tumor. In some cases, the addition of Racemetirosine to phenoxybenzamine plus propranolol has resulted in adequate control of symptoms previously unresponsive to the adrenergic blocking regimen. Drowsiness and sedation have been the most frequently reported side effects of Racemetirosine treatment.

Ambasilide, a class III antiarrhythmic, has been shown to block multiple cardiac channels in a variety of animals including humans. Ambasilide is a potassium channel antagonist. Ambasilide has multichannel blocking properties including beta-adrenergic antagonism.

Drobuline is a potent cardiac depressant (anti-arrhythmic) agent, which has been found to be effective against ventricular arrhythmias in dogs. This compound is a racemic mixture having a single center of optical activity. The two isomers of drobuline were found to be equally potent in converting cardiac arrhythmias in dogs after intravenous administration. The major route of biotransformation of drobuline in the dog was shown to be conjugation with glucuronic acid.