Piretanide (INN, trade names Arelix, Eurelix, Tauliz) has been synthesized in 1973 at Hoechst AG (Germany) as a loop diuretic[2] compound by using a then-new method for introducing cyclic amine residues in an aromatic nucleus in the presence of other aromatically bonded functional groups. Studies of piretanide in rats and dogs in comparison with other high-ceiling diuretics such as furosemide and bumetanide found a more suitable dose/response rate (regression line) and a more favourable sodium/potassium excretion ratio. These findings led eventually to clinical studies in man and finally to the introduction as a saluretic and antihypertensive medication in Germany, France, Italy and other countries.

Xibenolol or D-32 (dl-tert-butylamino-3-(2', 3'-dimethylphenoxy)-2-propanol hydrochloride) is a beta-blocking agent. It has been developing as a hypontesive medicine by Kowa Pharmaceutical and Teikoku Hormone, however development has been discontinued.

Watanidipine (AE0047) had been NDA filed for the treatment of hypertension in Japan. Watanidipine (as Calbren®) was awaiting registration with Mitsubishi Pharma Corporation in Japan. However, Mitsubishi Pharma Corporation has discontinued the development of this drug. Watanidipine had also been in phase II clinical trials for the treatment of stroke and preclinical trials for atherosclerosis. However, no recent development has been reported. Watanidipine (AE0047) has being shown to be a calcium antagonist with protective effects against cerebral ischaemia and the occurrence of stroke in several animal models.

TZC-5665 (Oberadilol) is a pyridazinone derivative with vasodilatory and beta-adrenergic blocking activities and type III phosphodiesterase inhibitory action

Tilisolol (, 4-[3-(tert-butylamino)- 2-hydroxyproxy]-N-methylisoeabostyril hydrochloride/N-696 ) is a non-selective beta-adrenergic blocking agent, and has a long-lasting and stable action in the clinical treatment of hypertension and angina pectoris. This antihypertensive effect of tilisolol might be largely attributable to its potent beta-adrenergic antagonistic effects. The measurement of the I-V relationship with or without tilisolol excluded the activation of ATP-sensitive K+ current (at least in cardiac muscle) under physiological conditions. However, several investigators suggested that tilisolol has a direct action on smooth muscle cells through ATP-sensitive K+ channels. The possibility that tilisolol has additional effects on the membrane ionic channels of cardiac myocytes under ischemic conditions remains to be tested. It was synthesized by Nisshin Hour Milling Co., Ltd. (Tokyo, Japan)

Todralazine is a hydralazinophthalazine-derived drug currently used in the treatment of arterial hypertension. As vasodilator, it might be used in combination with isosorbide dinitrate. Side effects and drug toxicity were uncommon in such vasodilator therapy.

Efonidipine is a 1,4-dihydropyridine derivative for the treatment of hypertension and angina. Efonidipine exerts its antihypertensive and antianginal effects through blocking L- and T-type calcium channels.

The Rauwolfia alkaloid, raubasine (ajmalicine), has been found to have broad application in the treatment of circulatory diseases, especially in the relief of obstruction of normal cerebral blood flow. In combination with other Rauwolfia alkaloids it has been used to lower high blood pressure. Raubasine is an antihypertensive drug used in the treatment of high blood pressure. It has been marketed under numerous brand names including Card-Lamuran, Circolene, Cristanyl, Duxil, Duxor, Hydroxysarpon, Iskedyl, Isosarpan, Isquebral, Lamuran, Melanex, Saltucin Co, Salvalion, and Sarpan. Raubasine acts as a α1-adrenergic receptor antagonist.

Cicletanine is a diuretic, developed by Ipsen for the treatment of hypertension. The drug was marketed in France by Recordati under the name Tenstaten. The mechanism(s) by which cicletanine exerts its biological effects has not been definitely established. The salidiuretic activity appears to be the result of an action of the sulfoconjugated metabolite of cicletanine, which inhibits the apical Na+-dependent Cl-/HCO3- anion exchanger in the distal convoluted tubule. The mechanism of the vasodilating effect of cicletanine may include stimulation of vascular prostaglandin synthesis, inhibition of the low Km cyclic GMP phosphodiesterases, and blockade of Ca2+ channels either directly or indirectly. The drug has also been shown to interact with other proteins, including alpha-adrenergic, vascular histamine, and muscarinic receptors.

Moxonidine is a second-generation, centrally acting antihypertensive drug with a distinctive mode of action. Moxonidine activates I1-imidazoline receptors (I1-receptors). Imidazoline I1-receptor agonism represents a new mode of antihypertensive action to inhibit peripheral alpha-adrenergic tone by a central mechanism. Adrenaline, noradrenaline and renin levels are reduced, a finding consistent with central inhibition of sympathetic tone. Moxonidine acts centrally to reduce peripheral sympathetic activity, thus decreasing peripheral vascular resistance. In patients with mild to moderate hypertension, moxonidine reduces blood pressure (BP) as effectively as most first-line antihypertensives when used as monotherapy and is also an effective adjunctive therapy in combination with other antihypertensive agents. It improves the metabolic profile in patients with hypertension and diabetes mellitus or impaired glucose tolerance, is well tolerated, has a low potential for drug interactions and may be administered once daily in most patients. Moxonidine is a good option in the treatment of patients with mild to moderate hypertension, particularly as adjunctive therapy in patients with the metabolic syndrome.