Beta blockers atenolol

Z. Pawlak and B. J. Clark, The assay and resolution of the beta-blocker atenolol from its related impurities, J. Pharm. Biomed. Anal., 70 329(1992). 

Hypertension and type 2 diabetes mellitus are frequent co-morbid conditions resulting in a very high risk population. ARBs - losartan as compared to the beta-blocker atenolol in the LIFE Study [8], candesartan as compared to the control therapies in the SCOPE [16] and CHARM [33] Studies, valsartan as compared to amlodipine in the VALUE Study [34] have been found to have beneficial effects in preventing the development of type 2 diabetes mellitus. 

Systemic absorption may occur when eye drops containing beta-blockers are administered. Beta-receptors are found in heart muscle (predominantly beta-1) and the smooth muscle of the blood vessels and bronchioles (mainly beta-2). Selective beta-blockers (atenolol, bisoprolol, metoprolol, nebivolol, acebutolol) primarily (but not exclusively) antagonize beta-1 receptors, while the non-selective drugs (carvedilol, celiprolol, esmolol, labetalol, nadolol, oxprenolol, pindolol, propanolol, sotalol, timolol) block both beta-1 and beta-2 receptors,... 

Page 95, figure 10.12 Redrawn after American Journal of Cardiology 87 823-826 (2001), Gottlieb S.S. et al. Comparative effects of three beta blockers (atenolol, metopro-lol, and propranolol) on survival after acute myocardial infarction. Reproduced with permission from Excerpta Medina Inc. 

Systemic beta-blockers are used extensively far the treatment of hypertension and other cardiovascular disorders. Of the available oral beta-blockers, atenolol, metoprolol, nadolol, pindolol, propranolol, and timolol have been documented to produce a dose-dependent reduction in lOP. The ocular hypotensive effect associated with systemically administered beta-blockers can be compared with that achieved with topically applied beta-blockers such as timolol. Although specific studies have not been conducted with most of the remaining systemic beta-blockers, these agents might also be expected to reduce lOP at clinically useful doses. 

This report documents a rare chnical reaction to ioxaglate, with a combination of a maculopapular rash, fever, hepatic and muscle involvement, eosinophiha, and a very high serum IgE concentration. The intradermal tests confirmed a delayed hypersensitivity reaction to ioxaglate. Histological examination of a skin biopsy identified the predominantly T lymphocyte nature of the infiltrate. A contributing role of the beta-blocker atenolol to the seriousness of the clinical syndrome must also be considered. 

The acid-base equilibrium constants of the beta-blockers atenolol, oxprenolol, timolol, and labetalol were determined by automated potentiometric titrations. The pKg values were obtained in water-rich or water methanol medium (20% MeOH) to obviate the solubility problems associated with the compounds. The initial estimates of pKa values were obtained from Gran s method and then, were refined by the NYTIT and ZETA versions of the LETAGROP computer program. The resultant values were 9.4 (/ = 0.1 M KCI, 20% methanol) for atenolol, 9.6 (/ = 0.1 M KCI) for oxprenolol, 9.4 (/ = 0.1 M KCI, 20% methanol) for timolol and 7.4 and 9.4 (/ = 0.1 M KCI) for labetalol. The potentiometric method was found to be accurate and easily applicable. The operational criteria for applying the methodology are indicated. 

Retrospective analysis of a large multinational study in patients given terazosin 5 or 10 mg daily found that terazosin only affected the blood pressure of patients taking beta blockers (atenolol, labetalol, metoprolol, sotalol, and timolol) if the blood pressure was uncontrolled. No change in blood pressure was seen in those with normal blood pressure (i.e. those without hypertension and those with hypertension controlled by beta blockers). The most common adverse effect in the 10-week terazosin phase was dizziness, and the incidence of this appeared to be lower in those taking antihypertensives (13 to 16%) than those not (21 to 25%)."... 

Beta blockers Atenolol, Metoprolol, Nadolol, Propranolol, Timolol... 

A study in 8 healthy subjects (5 of whom smoked 10 to 30 cigarettes daily) found that the clearance of a single 5.7 to 6.4 mg/kg dose of theophylline (as intravenous aminophylline) was reduced by 37% by propranolol 40 mg every 6 hours, when compared with theophylline alone. Metopro-lol 50 mg every 6 hours did not alter the clearance in the group as a whole, but the smokers had an 11% reduction in clearance. Another study, in 7 healthy subjects, found that the steady-state plasma clearance of theophylline was reduced by 30% by propranolol 40 mg every 8 hours, and by 52% by propranolol 240 mg every 8 hours. However, a further study found no significant pharmacokinetic interaction between theophylline and propranolol. Three other studies found that the cardioselective beta blockers atenolol 50 to 150 mg, - and bisoprolol 10 mg, and the non-se-... 

Biological factors may change the solubility or dissolution rate of the active substance from the medicinal product as well. The residence time in the stomach may increase the dissolution of poorly water-soluble active substances and change their bioavailabiUty. The pH in the stomach or the intestine may influence dissolutirm rates of acidic or basic active substances whose solubDity is pH-dependent. Bile salts may increase the dissolution rate and thereby the absorption of poorly water-soluble active substances such as ciclospoiine, phenytoin, levothyroxine and tacrolimus. Though, it has been shown that the association with bile acids reduces the absorption of the hydrophiUc beta-blocker atenolol. 

DiNicolantonio JJ, Lavie CJ, Fares H, Menezes AR, O Keefe JH (2013) Meta-analysis of carvedUol versus beta 1 selective beta-blockers (atenolol, bisopiolol, metoprolol, and nebivolol). Am J Cardiol 111 765-769... 

Nikolai LN, McClure EL, MacLeod SL, Wong CS (2006) Stereoisomer quantification of the Beta-blocker drugs atenolol, metoprolol, and propranolol in wastewaters by chiral high-performance liquid chromatography-tandem mass spectrometry. J Chromatogr A 1131 103-109... 

Now consider atenolol (marketed as Tenormin, among other names), a newer beta blocker that is specific for befa-1 receptors. Atenolol maintains all the good properties and therapeutic uses of propranolol but does not have the same potential to compromise lung function, a clear therapeutic advantage. There are a number of beta-1 specihc beta blockers in medical practice. The point is to hnd a molecule that does just one thing and does it very well. 

Beta Blockers. Beta blockers such as propranolol (Inderal) and atenolol (Tenormin) act by blocking the activity of the neurotransmitter norepinephrine. They have been nsed in the treatment of patients with panic disorder in an effort to alleviate the physical (antonomic) symptoms of the panic attack, bnt they proved no better than placebo and have no place in the treatment of panic disorder. 

The side effects of beta blockers include decreased blood pressure, dizziness, and sedation. They are also believed by some to worsen symptoms of depression in vulnerable individuals, though how beta blockers such as atenolol that do not enter the brain might do so is not readily understandable. In addition, beta blockers should be avoided in diabetic patients because they may dangerously mask the symptoms of hypoglycemia. Finally, beta blockers should not be taken by patients with emphysema (COPD) or asthma. 

Concurrent administration of beta-blockers, such as atenolol, and calcium-channel blockers may result in an enhanced hypotensive effect caused by an additive effect and heart failure may be precipitated. 

Common side-effects associated with beta-adrenoceptor blockers, such as atenolol, include fatigue, bradycardia, sleep disturbances, and peripheral vasoconstriction leading to coldness of extremities. Water-soluble beta-blockers, such as atenolol, are less likely to cause sleep disturbances and nightmares than lipid-soluble beta-blockers, such as propranolol. 

Concomitant use of calcium channel blockers (atenolol) Bradycardia and heart block can occur and the left ventricular end diastolic pressure can rise when beta-blockers are administered with verapamil or diltiazem. Patients with preexisting conduction abnormalities or left ventricular dysfunction are particularly susceptible. Recent acute Ml (sotalol) Sotalol can be used safely and effectively in the long-term treatment of life-threatening ventricular arrhythmias following an Ml. However, experience in the use of sotalol to treat cardiac arrhythmias in the early phase of recovery from acute Ml is limited and at least at high initial doses is not reassuring. 

Certain beta blockers have been shown to have an antimigraine effect, including propranolol, timolol, metroprolol, and atenolol. The beneficial effect appears to be comparable for the different drugs and independent of selective beta receptor blockage. 

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). 

Beta blockers without intrinsic sympathomimetic activity (eg, metoprolol, propranolol, atenolol) are effective therapeutic adjuncts in the management of thyrotoxicosis since many of these symptoms mimic those associated with sympathetic stimulation. Propranolol has been the 3 blocker most widely studied and used in the therapy of thyrotoxicosis. Beta blockers cause clinical improvement of hyperthyroid symptoms but do not typically alter thyroid hormone levels. Propranolol at doses greater than 160 mg/d may also reduce T3 levels approximately 20% by inhibiting the peripheral conversion of T4 to T3. 

Atenolol (Tenormin) [Antihypertensive, Antianginal/Beta Blocker] Uses HTN, angina, MI Action [3-Adrenergic receptor blocker... 

Beta blockers that bind to both beta-1 and beta-2 receptors (nonselective agents, see Table 20-2) may induce bronchoconstriction in patients with asthma or similar respiratory problems. These patients should be given one of the more cardioselective beta antagonists, such as atenolol (Tenormin) or metoprolol (Lopressor, others). Beta blockers may also produce excessive cardiac depression in individuals with certain types of cardiac disease. Beta blockers are generally well tolerated in most patients, however, and major problems are infrequent. 

---