Methods for treating hypertension and angina using salts of optically pure (-) amlodipine

Abstract

Methods and compositions are disclosed utilizing the optically pure (-) isomer of amlodipine. This compound is a potent drug for the treatment of hypertension while avoiding the concomitant liability of adverse effects associated with the racemic mixture of amlodipine. The (-) isomer of amlodipine is also useful for the treatment of angina and such other conditions as may be related to the activity of (-) amlodipine as a calcium channel antagonist such as cerebral ischemia, cerebral disorders, arrhythmias, cardiac hypertrophy, coronary vasospasm, myocardial infarction, renal impairment and acute renal failure, without the concomitant liability of adverse effects associated with the racemic mixture of amlodipine.

Description

1. BACKGROUND OF THE INVENTION[0001] This invention relates to novel compositions of matter containing optically pure (-) amlodipine. These compositions possess potent activity in treating both systolic and diastolic hypertension while avoiding adverse effects including but not limited to edema of the extremities, headache and dizziness, which are associated with administration of the racemic mixture of amlodipine. Additionally, these novel compositions of matter containing optically pure (-) amlodipine are useful in treating angina and such other conditions as may be related to the activity of (-) amlodipine as a calcium channel antagonist including but not limited to cerebral ischemia, cerebral disorders, arrhythmias, cardiac hypertrophy, coronary vasospasm, myocardial infarction, renal impairment and acute renal failure--while avoiding the adverse effects associated with administration of the racemic mixture of amlodipine. Also disclosed are methods for treating the above-describ...

AI Technical Summary

Problems solved by technology

Furthermore, optical purity is important since certain isomers may actually be deleterious rather than simply inert.

Its ability to block, calcium channels in smooth muscle produces peripheral vasodilation resulting in decreases in both systolic and diastolic blood pressure.

As stated above, the racemic mixture of amlodipine produces peripheral vasodilation, resulting in decreases in both systolic and diastolic blood pressure when used as an antihypertensive agent.

Nevertheless, hypertension results in chronic readjustment of cardiovascular hemodynamics, alteration of blood vessel walls, cardiovascular resistance and regional transmural pressures.

However, treatment of hypertension does not always correspondingly benefit the morbidity and mortality of the condition, either because chronic hypertension has produced other significant and irreversible cardiovascular changes, or because present drugs have an adverse effect on some other risk factor for cardiovascular disease.

Cerebral ischemia, often the result of atherosclerotic disease or hypertension, results from insufficient cerebral circulation.

However, cerebral ischemia may result from either an intra- or extracranial interruption of arterial blood flow.

If the ischemia lasts for a somewhat more extended period, infarction results and the resulting neurologic damage is permanent.

In the absence of treatment, symptoms vary with individual arrhythmias, but are often the consequence of inadequate cardiac filling and output and often include fatigue, decreased exercise tolerance, syncope, shortness of breath, nausea, lightheadedness and the like.

Cardiac hypertrophy can result from excessive workload either due to an obstruction to outflow, termed systolic overload, or to excessive volumes presented to the heart in diastole, termed diastolic overload.

Systolic overload results in concentric ventricular hypertrophy, in which there is an increased thickness in the walls of the heart not associated with increased volume.

An inadequate cardiac output results from the heart's failure in systolic or diastolic overload, leading to fatigue, shortness of breath, pulmonary congestion, edema and the like.

In an electrically unstable heart, diverse neural impulses to the heart may provoke coronary vascular spasm.

This may result in enhanced myocardial ischemia and arrhythmia, which in turn may culminate in ventricular fibrillation and sudden cardiac death.

The pain, which can be severe aching or pressure, leads to apprehension.

Congestive failure results in poor cardiac output and elevated left-ventricular diastolic pressure, leading to dyspnea, fatigue, peripheral edema, and coughing.

Classic migraine typically begins with visual auras followed by severe headaches, often accompanied by nausea and vomiting.

The most common cause of intrinsic renal failure is prolonged renal ischemia.

It is a structurally caused permanent or progressive decline in several dimensions of intellectual function that interferes substantially with individual normal social or economic activity.

The most common clinical picture is slow disintegration of personality and intellect due to impaired insight and judgment and loss of affect.

Memory impairment increases, beginning with problems recalling recent events or finding names.

Many calcium channel antagonists cause significant adverse effects.

In contrast to the situation with several other calcium channel antagonists, however, the racemic mixture of amlodipine has not been found to cause either marked or prolonged direct effects on heart rate or the reflex consequence of vasodilation.

However, the administration of the racemic mixture of amlodipine to a human has been found to cause still other adverse effects.

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