Beta-blockers hypertension with

Control of blood pressure in perioperative hypertension and in immediate postoperative period, CHF associated with acute Ml, angina pectoris unresponsive to recommended doses of nitrates or beta blockers... 

Beta Blockers. Most often used to treat hypertension, beta blockers also alleviate many of the readily visible physical (i.e., autonomic) symptoms of anxiety. Namely, these medications decrease the sweating, palpitations, racing pulse, dry mouth, and tremulousness that can accompany anxiety. Although beta blockers do not remedy the emotional aspects of anxiety, they can circumvent the spiraling anxiety of patients with social phobia who during performance situations become self-conscious of their readily evident physical symptoms. 

Nifedipine is a calcium-channel blocker of the dihydropyridine group. It relaxes smooth muscle and dilates both coronary and peripheral arteries by interfering with the inward displacement of calcium-channel ions through the active cell membrane. Unlike verapamil, nifedipine can be given with beta-blockers. Long-acting formulations of nifedipine are preferred in the long-term treatment of hypertension. 

Beta-blockers can no longer be considered as first line monotherapy for uncomplicated hypertension in older patients since some studies suggest they are less effective than diuretics and no better than placebo in reducing cardiovascular outcomes. Their use in elderly with hypertension probably should be confined to those with other indications such as angina, following myocardial infarction or with heart failure. 

Deficiency of adrenal medullary catecholamines appears to give no ill effects, and replacement therapy is therefore not used, but adrenal medullary tumours, phaeochromocytomas, secrete excess catecholamines often causing hypertension with dramatic episodes of headache, palpitations, pallor, sweating and anxiety. This condition is normally treated surgically, but preoperative preparation is mandatory to avoid catastrophic effects of surges of catecholamine release. A combination of alpha- and beta-adrenergic receptor blockade is normally used, with drugs such as phenoxybenzamine or doxazosin as alpha-blockers, and propranolol as a non-selective beta-blocker. 

Coadministration of beta-blockers can potentiate rebound hypertension upon discontinuation of medications, and it is therefore recommended that the beta-blocker be withdrawn before the tt2 agonist (Physicians Desk Reference, 2001). Tricyclic antidepressants may also produce changes in sinus node and AV conduction, and it is recommended that they be used cautiously in combination with tt2 agonists (Physicians Desk Reference, 2001). However, in child psychiatric practice, there has been debate about whether there are adverse interactions related to concomitant use of tricyclics and tt2 agonists. Finally, the tt2 agonists may potentiate the effects of CNS depressants (e.g., barbiturates) or other medications that produce sedation, so lower doses of each may be warranted. 

It is another nonselective beta blocker with longer duration of action and mainly used in hypertension. It is excreted largely in urine and does not cross blood-brain barrier and has no central side effects. 

It is a nonselective beta blocker with marked intrinsic sympathomimetic activity. It has advantage over propranolol that it produces less bradycardia and rebound hypertension. Oxprenolol resembles propranolol and is short acting with mild intrinsic sympathomimetic activity. Alprenolol is similar to pindolol and oxprenolol. 

Propranolol was the first blocker shown to be effective in hypertension and ischemic heart disease. Propranolol has now been largely replaced by cardioselective blockers such as metoprolol and atenolol. All B-adrenoceptor-blocking agents are useful for lowering blood pressure in mild to moderate hypertension. In severe hypertension, blockers are especially useful in preventing the reflex tachycardia that often results from treatment with direct vasodilators. Beta blockers have been shown to reduce mortality after a myocardial infarction and some also reduce mortality in patients with heart failure they are particularly advantageous for treating hypertension in patients with these conditions (see Chapter 13). 

Propranolol inhibits the stimulation of renin production by catecholamines (mediated by receptors). It is likely that propranolol s effect is due in part to depression of the renin-angiotensin-aldosterone system. Although most effective in patients with high plasma renin activity, propranolol also reduces blood pressure in hypertensive patients with normal or even low renin activity. Beta blockers might also act on peripheral presynaptic adrenoceptors to reduce sympathetic vasoconstrictor nerve activity. 

Bangalore S et al Beta-blockers for primary prevention of heart failure in patients with hypertension Insights from a meta-analysis. J Am Coll Cardiol 2008 52 1062. [PMID 18848139]... 

In 686 hypertensive men treated for 15 years, beta-blockers were associated with a higher incidence of diabetes than thiazide diuretics (200). This was an uncontrolled study, but the observation deserves further study. 

Alpha-adrenergic antagonists are used primarily as antihypertensive drugs because of their ability to block vascular alpha-1 receptors. Beta-adrenergic antagonists (beta blockers) are administered primarily for their inhibitory effects on myocardial function and are used in the prevention and treatment of hypertension, angina pectoris, arrhythmias, and myocardial reinfarction. Many of the drugs introduced in this chapter are discussed further in chapters that deal with the specific clinical conditions (e.g., hypertension, asthma, and other disorders). 

Jacob S, Henriksen EJ. Metabolic properties of vasodilating beta blockers management considerations for hypertensive diabetic patients and patients with the metabolic syndrome. J Clin Hypertens (Greenwich). 2004 6 690-696. 

The primary vasodilators used in hypertension are hydralazine (Apresoline) and minoxidil (Loniten) (Table 21-5). These drugs are not usually the first medications used in patients with hypertension, but tend to be added to the drug regimen if other agents (diuretics, beta blockers) fail.89 Hydralazine is likewise used to lower blood pressure in emergency situations... 

ACE inhibitors and angiotensin II blockers used to treat hypertension are listed in Table 21-5. These drugs have been shown to be effective in many cases of mild-to-moderate essential hypertension, and they may be used alone or in combination with beta blockers or diuretics. 

STEP 1 In patients with mild hypertension, drug therapy is usually initiated with a single agent (monotherapy) from one of the following classes a diuretic, a beta blocker, an angiotensin converting enzyme (ACE) inhibitor, or a calcium channel blocker. 

Acute intoxication with amphetamine is associated with tremor, confusion, irritability, hallucinations and paranoid behaviour, hypertension, sweating and occasionally cardiac arrhythmias convulsions and death may occur. The cardiovascular effects of the stimulants may be treated by beta-blockers, or by the combined alpha- and beta-blocker labetalol calcium channel antagonists such as nifedipine may correct the arrhythmias, while intravenous diazepam is of value in attenuating seizures. 

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