Ischemic heart disease beta-blockers

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). 

People with diabetes have a much worse outcome after acute myocardial infarction, with a mortality rate at least twice that in non-diabetics. However, tight control of blood glucose, with immediate intensive insulin treatment during the peri-infarct period followed by intensive subcutaneous insulin treatment, was associated with a 30% reduction in mortality at 1 year, as reported in the DIGAMI study. In addition, the use of beta-blockers in this group of patients had an independent secondary preventive effect (198). The use of beta-blockers in diabetics with ischemic heart disease should be encouraged (199). 

The adverse effects of beta-blockers are usually mild, with occurrence rates of 10-20% for the most common in most studies. Most are predictable from the pharmacological and physicochemical properties of these drugs. Examples include fatigue, cold peripheries, bradycardia, heart failure, sleep disturbances, bronchospasm, and altered glucose tolerance. Gastrointestinal upsets are also relatively common. Serious adverse cardiac effects and even sudden death can follow abrupt withdrawal of therapy in patients with ischemic heart disease. Most severe adverse reactions can be avoided by careful selection of patients and consideration of individual beta-blockers. Hjrpersensitivity reactions have been relatively rare since the withdrawal of practolol. Tumor-inducing effects have not been estabhshed in man. 

In symptomatic chronic heart failure, beta-blockers are also an essential component of an optimal medical regimen, as demonstrated in several trials (95-98). Currently extended-release metoprolol succinate, carve-dilol, and bisoprolol remain the agents of choice for treatment of patients with chronic ischemic heart disease and NYHA Class II-IV symptomatic heart failure. 

Flaherty, J. T. (1992). The role of nitrates in acute myocardial infarction and post-infarction. In Medical Therapy of Ischemic Heart Disease Nitrates, Beta Blockers and Calcium Antagonists , (J. Abrams, C. J. Pepine, and U. Thadani, eds.), pp. 309-328. Little, Brown, Boston. 

Propranolol and other beta blockers have received enormous clinical attention because of their effectiveness in treating hypertension (high blood pressure), migraine headaches, glaucoma, ischemic heart disease, and certain cardiac arrhythmias. The hydrochloride salt of propranolol has been marketed under at least 30 brand names, one of which is Cardinol . (Note the "card-" part of the name, after cardiac.)... 

For some of these diseases, such as hypertension and heart disease, drugs such as ACE inhibitors and beta-blockers are available for treatment. For some other diseases, such as Alzheimer s disease, more effective drugs have yet to be discovered. For stroke, two late stage (Phase III) trials of NXY-059 and desmoteplase failed to meet the trial criteria. Other clinical trials in progress for ischemic stroke are presented in Table 11.1. 

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