Calcium channel antagonists blockers

In the treatment of hypertension, ACE inhibitors are as effective as diuretics, (3-adrenoceptor antagonists, or calcium channel blockers in lowering blood pressure. However, increased survival rates have only been demonstrated for diuretics and (3-adrenoceptor antagonists. ACE inhibitors are approved for monotherapy as well as for combinational regimes. ACE inhibitors are the dtugs of choice for the treatment of hypertension with renal diseases, particularly diabetic nephropathy, because they prevent the progression of renal failure and improve proteinuria more efficiently than the other diugs. 

ACE inhibitors - AT antagonists - Alpha blockers - Beta blockers Isolated syslolic hypertension (older patienls) - Diuretics preferred (generally Thiazides) - Long-acting dihydropyridine calcium channel blocker... 

The dihydropyridine-sensitive Cav1.2 calcium channel, that is essential for smooth muscle contration and the target for the calcium channel blocker/calcium antagonists. 

Although there is no evidence that the neuronal degeneration of AzD results, as in cardiovascular ischaemia, from the excitotoxicity of increased intracellular Ca +, some calcium channel blockers have been tried in AzD. They have had little effect but surprisingly a pyrrolidone derivative nefiracetam, which opens L-type voltage-sensitive calcium channels (VSCCs) reduces both scopolamine- and )S-amyloid-induced impairments of learning and memory in rats (Yamada et al. 1999). This effect can be overcome by VSCC antagonists, but nefiracetam has not been tried in humans. 

Patients with asymptomatic left ventricular systolic dysfunction and hypertension should be treated with P-blockers and ACE inhibitors. Those with heart failure secondary to left ventricular dysfunction and hypertension should be treated with drugs proven to also reduce the morbidity and mortality of heart failure, including P-blockers, ACE inhibitors, ARBs, aldosterone antagonists, and diuretics for symptom control as well as antihypertensive effect. In African-Americans with heart failure and left ventricular systolic dysfunction, combination therapy with nitrates and hydralazine not only affords a morbidity and mortality benefit, but may also be useful as antihypertensive therapy if needed.66 The dihydropyridine calcium channel blockers amlodipine or felodipine may also be used in patients with heart failure and left ventricular systolic dysfunction for uncontrolled blood pressure, although they have no effect on heart failure morbidity and mortality in these patients.49 For patients with heart failure and preserved ejection fraction, antihypertensive therapies that should be considered include P-blockers, ACE inhibitors, ARBs, calcium channel blockers (including nondihydropyridine agents), diuretics, and others as needed to control blood pressure.2,49... 

The effects of corticosteroids, cyclooxygenase blockers, leukotriene blockers, PAF antagonists, anti-TNF antibodies, oxygen radical scavengers, opiate antagonists, antihistamines, and calcium channel blockers in endotoxic shock were reviewed in 1990 (H17). In this section studies on this subject that have been published during the last few years are summarized. 

Another possibility is that the antagonist interferes with other post-receptor events that contribute to the tissue response. For example, calcium channel blockers such as verapamil block the influx of calcium necessary for maintained smooth muscle contraction hence, they reduce the contractile response to acetylcholine. Some pharmacologists prefer to describe this as a variant of functional antagonism (see above). 

Safer antihypertensives include angiotensinconverting enzyme inhibitors, postsynap-tic a,-adrenergic antagonists (terazosin, doxazosin), calcium channel blockers, and angiotensin II antagonists. 

Many different drug classes have shown to cause hypotension and orthostatic reactions and drugs for cardiovascular conditions, psychoactive medicines and polypharmacy, can all have this side effect (Box 5.15). Among the most frequently used drugs in the elderly are diuretics, ACE-inhibitors, angiotensin II antagonists, calcium channel blockers and antidepressants. 

Heart medication, betablockers, ACE-inhibitors, long acting nitro derivates, calcium channel blockers, angiotensin II antagonists... 

These drugs were developed as coronary vasodilating agents and were used for that purpose for some time, until it was discovered that they inhibit the contractile effect of calcium on smooth musculature and cardiac muscle, and that they affect calcium channels on the cell surface that permit calcium ions to enter. At first, they were called calcium antagonists however, later on this class of compounds was given the preferred name of calcium channel blockers. 

Drugs that may affect sulfonylureas include androgens, anticoagulants, azole antifungals, barbiturates, beta blockers, calcium channel blockers, charcoal, chloramphenicol, cholestyramine, ciprofloxacin, clofibrate, corticosteroids, diazoxide, estrogens, ethanol, fluconazole, gemfibrozil, histamine H2 antagonists, hydantoins,... 

Available evidence suggests that a single unifying mechanism does not exist but rather that various vasodilators may act at different places in the series of processes that couple excitation of vascular smooth muscle cells with contraction. For example, the vasodilators known as calcium channel antagonists block or limit the entry of calcium through voltage-dependent channels in the membrane of vascular smooth muscle cells. In this way, the calcium channel blockers limit the amount of free intracellular calcium available to interact with smooth muscle contractile proteins (see Chapter 14). 

Cinnarizine is an H 1-receptor antagonist and a calcium channel blocker used for the treatment of vertigo and emetic symptoms due to Meniere s disease and related labyrinth disorders. It is also effective in motion sickness. It is used for peripheral and cerebral vascular disorders, because of its calcium channel blocking properties. 

Combined therapy using calcium channel blockers with p-adrenoceptor antagonists is increasingly common, and is probably safest with the dihydropyridines. Synergy occurs that can lead to marked interference with... 

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