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.

Conivaptan is an arginine vasopressin (AVP) receptor antagonist with affinity for AVP receptor subtypes V1A and V2. The antidiuretic action of AVP is mediated through activation of the V2 receptor, which functions to regulate water and electrolyte balance at the level of the collecting ducts in the kidney. Conivaptan was approved in 2004 for hyponatremia caused by syndrome of inappropriate antidiuretic hormone. Conicaptan is being evaluated for reduce intracranial pressure in patients with traumatic brain injury, and as a treatment for heart failure.

Candesartan is classified as an angiotensin II receptor type 1 antagonist. Candesartan is an orally active lipophilic drug and possesses rapid oral absorption. It causes a reduction in blood pressure and is used in the treatment of hypertension. It is also used in the treatment of congestive heart failure and given as prophylaxis to reduce the severity and duration of migraine. Candesartan cilexetil, a prodrug of Candesartan, is available in the market under the trade names Atacand, Amias. Candesartan cilexetil is rapidly converted to candesartan, its active metabolite, during absorption from the gastrointestinal tract. Candesartan confers blood pressure lowering effects by antagonizing the hypertensive effects of angiotensin II via the RAAS (renin–angiotensin–aldosterone system). RAAS is a homeostatic mechanism for regulating hemodynamics, water, and electrolyte balance. During sympathetic stimulation or when renal blood pressure or blood flow is reduced, renin is released from granular cells of the juxtaglomerular apparatus in the kidneys. Renin cleaves circulating angiotensinogen to angiotensin I, which is cleaved by angiotensin converting enzyme (ACE) to angiotensin II. Angiotensin II increases blood pressure by increasing total peripheral resistance, increasing sodium and water reabsorption in the kidneys via aldosterone secretion, and altering the cardiovascular structure. Angiotensin II binds to two receptors: type-1 angiotensin II receptor (AT1) and type-2 angiotensin II receptor (AT2). Candesartan selectively blocks the binding of angiotensin II to AT1 in many tissues including vascular smooth muscle and the adrenal glands. This inhibits the AT1-mediated vasoconstrictive and aldosterone-secreting effects of angiotensin II and results in an overall decrease in blood pressure. Candesartan is greater than 10,000 times more selective for AT1 than AT2.

There is no information in the literature about pharmacological and biological application of definite isomer of valsatran, R – form (also known as VALSARTAN, D- or CGP-49309). However there were found, that in the tablets of valsartan, which are used to treat high blood pressure and to heart failure, the R-enantiomer was an impurity.

Losartan is a selective, competitive angiotensin II receptor type 1 (AT1) antagonist. Losartant is recommended as one of several preferred agents for the initial management of hypertension. Administration of losartan reduces the risk of stroke in patients with hypertension and left ventricular hypertrophy. Losartan is indicated for the treatment of diabetic nephropathy with an elevated serum creatinine and proteinuria in patients with type 2 diabetes and a history of hypertension.

Carvedilol competitively blocks β1, β2 and α1 receptors. The drug lacks sympathomimetic activity and has vasodilating properties that are exerted primarily through α1-blockade. Animal models indicate that carvedilol confers protection against myocardial necrosis, arrhythmia and cell damage caused by oxidising free radicals, and the drug has no adverse effects on plasma lipid profiles. COREG® (carvedilol) is a racemic mixture in which nonselective β-adrenoreceptor blocking activity is present in the S(-) enantiomer and α1-adrenergic blocking activity is present in both R(+) and S(-) enantiomers at equal potency. Carvedilol is the first drug of its kind to be approved for the treatment of congestive heart failure, and is now the standard of care for this devastating disease. Carvedilol is also confirmed as effective in the management of mild to moderate hypertension and ischaemic heart disease.

Lisinopril is a potent, competitive inhibitor of angiotensin-converting enzyme (ACE). Lisinopril is marketed under the brand name ZESTRIL. ZESTRIL is indicated for the treatment of hypertension. It may be used alone as initial therapy or concomitantly with other classes of antihypertensive agents. It is also indicated as adjunctive therapy in the management of heart failure in patients who are not responding adequately to diuretics and digitalis. Lisinopril inhibits angiotensin-converting enzyme (ACE) in human subjects and animals. ACE is a peptidyl dipeptidase that catalyzes the conversion of angiotensin I to the vasoconstrictor substance, angiotensin II. Angiotensin II also stimulates aldosterone secretion by the adrenal cortex. The beneficial effects of lisinopril in hypertension and heart failure appear to result primarily from suppression of the renin-angiotensin-aldosterone system. Inhibition of ACE results in decreased plasma angiotensin II which leads to decreased vasopressor activity and to decreased aldosterone secretion. While the mechanism through which ZESTRIL lowers blood pressure is believed to be primarily suppression of the renin-angiotensin-aldosterone system, ZESTRIL is antihypertensive even in patients with low-renin hypertension.

Enalapril (marketed as Vasotec in the US, Enaladex and Renitec in some other countries) is an angiotensin-converting-enzyme (ACE) inhibitor used in the treatment of hypertension, diabetic nephropathy, and some types of chronic heart failure. Enalapril, after hydrolysis to enalaprilat, inhibits angiotensin-converting enzyme (ACE) in human subjects and animals. ACE is a peptidyl dipeptidase that catalyzes the conversion of angiotensin I to the vasoconstrictor substance, angiotensin II. Angiotensin II also stimulates aldosterone secretion by the adrenal cortex. The beneficial effects of enalapril in hypertension and heart failure appear to result primarily from suppression of the renin-angiotensin-aldosterone system. Inhibition of ACE results in decreased plasma angiotensin II, which leads to decreased vasopressor activity and to decrease aldosterone secretion.

Amiloride, an antikaliuretic-diuretic agent, is a pyrazine-carbonyl-guanidine that is unrelated chemically to other known antikaliuretic or diuretic agents. It is an antihypertensive, potassium-sparing diuretic that was first approved for use in 1967 and helps to treat hypertension and congestive heart failure. The drug is often used in conjunction with thiazide or loop diuretics. Due to its potassium-sparing capacities, hyperkalemia (high blood potassium levels) are occasionally observed in patients taking amiloride. Amiloride works by inhibiting sodium reabsorption in the distal convoluted tubules and collecting ducts in the kidneys by binding to the amiloride-sensitive sodium channels. This promotes the loss of sodium and water from the body, but without depleting potassium. It is used for as adjunctive treatment with thiazide diuretics or other kaliuretic-diuretic agents in congestive heart failure or hypertension.

Digoxin, a cardiac glycoside similar to digitoxin, is used to treat congestive heart failure and supraventricular arrhythmias due to reentry mechanisms, and to control ventricular rate in the treatment of chronic atrial fibrillation. Digoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium. The sodium calcium exchanger (NCX) in turn tries to extrude the sodium and in so doing, pumps in more calcium. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). Digoxin also acts on the electrical activity of the heart, increasing the slope of phase 4 depolarization, shortening the action potential duration, and decreasing the maximal diastolic potential.