Ranolazine for the Treatment of Chronic Angina and Potential Use in Other Cardiovascular Conditions

Abstract

Chronic angina, a condition that impairs quality of life and is associated with decreased life expectancy, affects &6.4 million Americans.1 Current therapies that reduce angina frequency and nitrate consumption and increase the threshold at which demand-induced myocardial ischemic symptoms become evident include drugs (nitrates, β-blockers, calcium antagonists), exercise conditioning, enhanced external counterpulsation, and coronary revascularization.1–3 Several new investigational drugs are being tested for the treatment of chronic angina.4–9 This review will focus on sustained-release ranolazine, a drug that reduces angina symptoms, with a mechanism of action different from that of currently available pharmacological therapies.8–29 Ranolazine was approved on January 27, 2006, in the United States for use in patients with chronic angina who continue to be symptomatic on β-blockers, calcium antagonists, or nitrates. Ranolazine ([(+) N -(2,6-dimethylphenyl)-4(2-hydroxy-3-(2-methoxyphenoxy)-propyl)-1-piperazine acetamide dihydrochloride]) is an active piperazine derivative that was patented in 1986 and is available in an oral and intravenous form (Figure 1). The immediate-release ranolazine (not in current use) had an average terminal elimination half-life ranging from 1.4 to 1.9 hours and a 10-fold peak/trough difference with dosing of 240 to 400 mg 3 times per day.19 Early studies with immediate-release ranolazine provided evidence of antiischemic/antianginal properties in patients with chronic angina without clinically significant changes in heart rate or blood pressure and are reviewed elsewhere.20–24 Unless otherwise stated, the remainder of this review refers to sustained-release ranolazine. Figure 1. Chemical structure and metabolism of ranolazine. Reprinted with permission from J Clin Pharmacol . 2005;45:422–433.17 Ranolazine (Ranexa; CV Therapeutics Inc, Palo Alto, Calif) is manufactured in a sustained-release form that has a prolonged absorption phase with maximal plasma concentrations (Cmax) typically seen 4 to 6 hours after administration. The average terminal elimination half-life is &7 hours after multiple dosing to steady state, and the …