ranolazine brands

Molecular formula: C24H33N3O4

Myocardial ischemia exerts effects on adenosine triphosphate flux, leading to a decrease in the energy available for contraction and relaxation of the heart muscle. Electrolyte balance of sodium and potassium is necessary for maintaining normal cardiac contraction and relaxation. Disruption of adequate sodium and potassium electrolyte balance leads to excessively high concentrations of sodium and calcium, which likely interferes with oxygen supply to the heart muscle. This imbalance eventually leads to angina symptoms of chest pain or pressure, nausea, and dizziness, among others. The mechanism of action for ranolazine is not fully understood. At therapeutic concentrations, it can inhibit the cardiac late sodium 205 current (INa), which may affect the electrolyte balance in the myocardium, relieving angina symptoms. The clinical significance this inhibition in the treatment of angina symptoms is not yet confirmed. Ranolazine inhibits sodium and potassium ion channel currents. It has been shown to exert weak activity on L-type calcium channels making it a weak direct vasodilator and exerts minimal direct effects on atrioventricular nodal conduction. Some additional mechanisms have been elucidated. Ranolazine exerts antagonistic activity towards the alpha 1 and beta 1 adrenergic receptors and inhibition of fatty acid oxidation. Ranolazine, a piperazine derivative, is an antianginal agent. Although the exact mechanism of antianginal activity of ranolazine has not been fully elucidated, results of early studies suggested that ranolazine shifted adenosine triphosphate (ATP) production away from fatty acid oxidation (ie, partial inhibition of fatty acid oxidation) in favor of more oxygen-efficient glucose oxidation, especially when free fatty acid concentrations were elevated (eg, during ischemia), leading to reduced oxygen demand and symptoms of ischemia without affecting cardiac work. However, these pharmacologic effects generally were observed at concentrations exceeding therapeutic plasma concentrations in clinical studies. Recent data suggest that ranolazine may exert its antianginal and anti-ischemic effects through concentration-, voltage-, and frequency-dependent inhibition of the late (ie, sustained, persistent) sodium current and other cardiac ion channels and transporters. The late sodium current is created by inactivation of the sodium channel protein. However, angina (ie, ischemia, hypoxia) impairs sodium channel inactivation and increases the amount of sodium in cardiac cells, which facilitates calcium overload via the sodium-calcium exchange pump. Increased intracellular calcium may result in myocyte hyperexcitability and electrical instability, impaired diastolic relaxation, reduced coronary artery perfusion, impaired myocardial oxygen supply, increased oxygen demand, and ventricular dysfunction. Thus, ranolazine may decrease the magnitude of the late sodium current resulting in a net reduction in intracellular sodium concentrations, reversal of calcium overload, restoration of ventricular pump function, and prevention of ischemia-induced arrhythmias. Unlike other antianginal agents, the antianginal effects of ranolazine are not dependent upon reductions in heart rate or blood pressure. The QT prolongation effect of ranolazine on the surface electrocardiogram is the result of inhibition of IKr, which prolongs the ventricular action potential. /The authors/ investigated changes in Na(+) currents (I(Na)) in permanent (or chronic) atrial fibrillation (AF) and the effects of I(Na) inhibition using ranolazine (Ran) on arrhythmias and contractility in human atrial myocardium. Electrical remodeling during AF is typically associated with alterations in Ca(2+) and K(+) currents. It remains unclear whether I(Na) is also altered. Right atrial appendages from patients with AF (n = 23) and in sinus rhythm (SR) (n = 79) were studied. Patch-clamp experiments in isolated atrial myocytes showed significantly reduced peak I(Na) d

Source: PubChem (NCBI) · compound 56959