Imidapril (Tanatril), through its active metabolite imidaprilat, acts as an ACE inhibitor to suppress the conversion of angiotensin I to angiotensin II and thereby reduce total peripheral resistance and systemic blood pressure (BP). In clinical trials, oral imidapril was an effective antihypertensive agent in the treatment of mild to moderate essential hypertension. Some evidence suggests that imidapril also improves exercise capacity in patients with chronic heart failure (CHF) and reduces urinary albumin excretion rate in patients with type 1 diabetes mellitus. Imidapril was well tolerated, with a lower incidence of dry cough than enalapril or benazepril, and is a first choice ACE inhibitor for the treatment of mild to moderate essential hypertension.

Benidipine is an orally triple L-, T-, and N-type calcium channel blocker for the treatment of hypertension and angina pectoris synthesized and developed by Kyowa Hakko Kogyo Co., Ltd. Benidipine, approved in Japan in November 1991, has become one of the three best selling CCBs and is highly useful as a potent, long-lasting antihypertensive and antianginal agent.

Bamidipine is an antihypertensive drug belonging to the dihydropyridine (DHP) group of calcium antagonists. The product was originally developed by Yamanouchi Pharmaceutical (Tokyo, Japan) and is currently marketed in Japan under the trade name of Hypoca (Astellas Pharma Inc, Tokyo, Japan). It is available in a modified-release formulation which has a gradual onset of action and is effective in a single daily oral dose of 10 to 20 mg. Bamidipine has selective action against cardiovascular calcium antagonist receptors and its antihypertensive action is related to the reduction of peripheral vascular resistance secondary to its vasodilatory action. The clinical antihypertensive efficacy of barnidipine is similar to that of other DHP calcium antagonists such as nitrendipine and amlodipine, and antihypertensives belonging to other drug classes such as atenolol and enalapril. Barnidipine has been found to be as efficacious and well tolerated as hydrochlorothiazide in the management of hypertension in elderly patients. Barnidipine is generally well tolerated. As with other DHP calcium antagonists, vasodilator adverse events such as headache, flushing and peripheral oedema account for most of the adverse events reported with its use and are usually transient. Oedema is less frequent than with amlodipine and nitrendipine. Its use is not associated with reflex tachycardia.

Proroxan is a non-selective а-adrenoblocker. Proroxan was found to prevent the development of hypertensive crises and improve cerebral bioelectrical parameters in most of hypertensive patients. Proroxan has been used as an antihypertensive and in the treatment of Ménière’s disease, motion sickness, and allergic dermatitis.

Camostat mesilate (FOY-305) is a synthetic f low-molecular weight protease inhibitor. It is able to inhibit trypsin, prostasin, matriptase and plasma kallikrein. In addition camostat attenuates airway epithelial sodium channel function and enhances mucociliary clearance. Camostat mesilate tablets (FOIPAN®) are approved in Japan and used for the treatment of remission of acute symptoms of chronic pancreatitis and postoperative reflux esophagitis.

Guanoclor is an anti-hypertensive agent developed by Pfizer Ltd. (U.K.). It seems to be effective in various types of hypertension (unknown aetiology, renal, and malignant). It affects both systolic blood-pressure and diastolic blood-pressure. It is an adrenergic neurone-blocking agent, which also interferes with noradrenaline synthesis by inhibition of the enzyme dopamine beta-hydroxylase. Clinical use of the compound was first reported by Lawrie et al. (1964), who achieved satisfactory blood-pressure control in 60% of their cases with guanoclor alone, and in a further 18% with the addition of a thiazide diuretic. They also noted a significant reduction in urinary noradrenaline levels during guanoclor administration. Guanochlor has an affinity for the Na+/H+ exchanger ranging between 0.5 uM and 6 uM in different systems and is more potent than amiloride in all systems studied. It is suggested that guanochlor recognizes a binding site on the Na+/H+ exchanger that is distinct from the amiloride binding site.

Temocapril is a prodrug-type angiotensin-I converting enzyme (ACE) inhibitor not approved for use in the United States but is approved in Japan and South Korea. Temocapril can also be used in hemodialysis patients without risk of serious accumulation.

Dilevalol, the RR-stereoisomer of labetalol, is a non-cardioselective β-adrenoceptor antagonist with substantial partial β2-agonist and negligible α1-blocking activity. Reduction in blood pressure during dilevalol administration is associated with peripheral vasodilatation, and heart rate remains essentially unchanged. Following oral administration, dilevalol is completely absorbed. Once-daily administration is possible, due to a long elimination half-life. In vitro and in vivo animal studies and results obtained in humans reveal that dilevalol is a nonselective blocker of β1- and β2-adrenoceptors, with a similar potency to propranolol, but has negligible antagonistic activity at α1-receptors. Dilevalol, the R,R′ stereoisomer, makes up 25% of racemic labetalol, the drug, approved by FDA for the treatment of hypertension. The relaxing potency of dilevalol was approximately 4.7 times more potent than that of labetalol. Dilevalol markedly reduced the diastolic blood pressure with only a slight increase of heart rate In pithed rats, while isoproterenol and pindolol caused moderate to marked positive chronotropic effects in proportion to their hypotensive effects. These results suggest that dilevalol has more potent ISA than labetalol. In contrast to labetalol, dilevalol possesses little, if any, alpha-adrenergic blocking activity. The compound is 3 to 10 times less potent than labetalol at α1-adrenergic receptors under a variety of experimental conditions. Moreover, it is 300- to 1000-fold less potent at alpha1-adrenergic receptors compared with β1-adrenergic receptors. The pA2 values for dilevalol as an α antagonist range from 5.9 to 6.4. Because maximal plasma concentrations of the drug after administration of a 400-mg dose are approximately 0.5 pmol, it is doubtful that alpha blockade is involved in the antihypertensive response to dilevalol in humans.

(-)-Propranolol is a small molecule β-adrenergic receptor antagonist and the active isomer of (±)-Propranolol preparations. (-)-Propranolol blocks the binding of epinephrine, norepinephrine, and other endogenous catecholamines to the β-adrenergic receptor, impeding increases in cardiac flow velocity and general stimulation of the sympathetic nervous system signaled by the association of these molecules to the β-adrenergic receptor. In addition to blockade of agonist binding, antagonism of the β-adrenergic receptor by (-)-Propranolol produces negative chronotropic and inotropic action, effectively dampening the force and rate of cardiac contraction. These negative chronotropic and inotropic effects correlate to a demonstrated suppression of adrenaline-induced cardiac arrhythmia by (-)-Propranolol. Suppression of β-adrenergic receptor activation by (-)-Propranolol has been widely exploited in counteracting situations sensitive to heightened cardiac activity including hypertension, angina pectoris, and cardiac ischemia.

Zofenopril is an inhibitor of Angiotensin Converting Enzyme (ACE), which is approved in Europe for the treatment of hypertension and acute myocardial infarction.