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Pharmacotherapeutic Group: Other cardiac preparations. ATC Code: C01EB18.
Pharmacology: Pharmacodynamics: Mechanism of action: The mechanism of action of ranolazine is largely unknown. Ranolazine may have some antianginal effects by inhibition of the late sodium current in cardiac cells. This reduces intracellular sodium accumulation and consequently decreases intracellular calcium overload. Ranolazine, via its action to decrease the late sodium current, is considered to reduce these intracellular ionic imbalances during ischaemia. This reduction in cellular calcium overload is expected to improve myocardial relaxation and thereby decrease left ventricular diastolic stiffness. Clinical evidence of inhibition of the late sodium current by ranolazine is provided by a significant shortening of the QTc interval and an improvement in diastolic relaxation in an open-label study of 5 patients with a long QT syndrome (LQT3 having the SCN5A ΔKPQ gene mutation).
These effects do not depend upon changes in heart rate, blood pressure, or vasodilation.
Pharmacodynamic effects: Haemodynamic effects: Minimal decreases in mean heart rate (< 2 beats per minute) and mean systolic blood pressure (< 3 mm Hg) were observed in patients treated with ranolazine either alone or in combination with other antianginal medicinal products in controlled studies. Electrocardiographic effects: Dose and plasma concentration-related increases in the QTc interval (about 6 msec at 1000 mg twice daily), reductions in T wave amplitude, and in some cases notched T waves, have been observed in patients treated with Ranexa. These effects of ranolazine on the surface electrocardiogram are believed to result from inhibition of the fast-rectifying potassium current, which prolongs the ventricular action potential, and from inhibition of the late sodium current, which shortens the ventricular action potential. A population analysis of combined data from 1,308 patients and healthy volunteers demonstrated a mean increase in QTc from baseline of 2.4 msec per 1000 ng/ml ranolazine plasma concentration. This value is consistent with data from pivotal clinical studies, where mean changes from baseline in QTcF (Fridericia's correction) after doses of 500 and 750 mg twice daily were 1.9 and 4.9 msec, respectively. The slope is higher in patients with clinically significant hepatic impairment.
In a large outcome study (MERLIN-TIMI 36) in 6,560 patients with UA/NSTEMI ACS, there was no difference between Ranexa and placebo in the risk of all-cause mortality (relative risk ranolazine:placebo 0.99), sudden cardiac death (relative risk ranolazine:placebo 0.87), or the frequency of symptomatic documented arrhythmias (3.0% versus 3.1%).
No proarrhythmic effects were observed in 3,162 patients treated with Ranexa based on 7-day Holter monitoring in the MERLIN-TIMI 36 study. There was a significantly lower incidence of arrhythmias in patients treated with Ranexa (80%) versus placebo (87%), including ventricular tachycardia ≥ 8 beats (5% versus 8%).
Clinical efficacy and safety: Clinical studies have demonstrated the efficacy and safety of Ranexa in the treatment of patients with chronic angina, either alone or when the benefit from other antianginal medicinal products was sub-optimal.
In the pivotal study, CARISA, Ranexa was added to treatment with atenolol 50 mg once daily, amlodipine 5 mg once daily, or diltiazem 180 mg once daily. Eight-hundred and twenty-three patients (23% women) were randomised to receive 12 weeks of treatment with Ranexa 750 mg twice daily, 1000 mg twice daily, or placebo. Ranexa demonstrated greater efficacy than placebo in prolonging exercise time at trough at 12 weeks for both doses studied when used as an add-on therapy. However, there was no difference in exercise duration between the two doses (24 seconds compared to placebo; p ≤ 0.03).
Ranexa resulted in significant decreases in the number of angina attacks per week and consumption of short-acting nitroglycerin compared to placebo. Tolerance to ranolazine did not develop during treatment and a rebound increase in angina attacks was not observed following abrupt discontinuation. The improvement in exercise duration in women was about 33% of the improvement in men at the 1000 mg twice-daily dose level. However, men and women had similar reductions in frequency of angina attacks and nitroglycerin consumption. Given the dose-dependent side effects and similar efficacy at 750 and 1000 mg twice daily, a maximum dose of 750 mg twice daily is recommended.
In a second study, ERICA, Ranexa was added to treatment with amlodipine 10 mg once daily (the maximum labelled dose). Five-hundred and sixty-five patients were randomised to receive an initial dose of Ranexa 500 mg twice daily or placebo for 1 week, followed by 6 weeks of treatment with Ranexa 1000 mg twice daily or placebo, in addition to concomitant treatment with amlodipine 10 mg once daily. Additionally, 45% of the study population also received long-acting nitrates. Ranexa resulted in significant decreases in the number of angina attacks per week (p = 0.028) and consumption of short-acting nitroglycerin (p = 0.014) compared to placebo. Both the average number of angina attacks and nitroglycerin tablets consumed decreased by approximately one per week.
In the main dose-finding study, MARISA, ranolazine was used as monotherapy. One-hundred and ninety-one patients were randomised to treatment with Ranexa 500 mg twice daily, 1000 mg twice daily, 1500 mg twice daily, and matching placebo, each for 1 week in a crossover design. Ranexa was significantly superior to placebo in prolonging exercise time, time to angina, and time to 1 mm ST segment depression at all doses studied with an observed dose-response relationship. Improvement of exercise duration was statistically significant compared to placebo for all three doses of ranolazine from 24 seconds at 500 mg twice daily to 46 seconds at 1500 mg twice daily, showing a dose-related response. In this study, exercise duration was longest in the 1500 mg group; however, there was a disproportional increase in side effects, and the 1500 mg dose was not studied further.
In a large outcome study (MERLIN-TIMI 36) in 6,560 patients with UA/NSTEMI ACS, there was no difference in the risk of all-cause mortality (relative risk ranolazine:placebo 0.99), sudden cardiac death (relative risk ranolazine:placebo 0.87), or the frequency of symptomatic documented arrhythmias (3.0% versus 3.1%) between Ranexa and placebo when added to standard medical therapy (including beta-blockers, calcium channel blockers, nitrates, anti-platelet agents, lipid-lowering medicinal products, and ACE inhibitors). Approximately one-half of the patients in MERLIN-TIMI 36 had a history of angina. The results showed that exercise duration was 31 seconds longer in ranolazine patients versus placebo patients (p = 0.002). The Seattle Angina Questionnaire showed significant effects on several dimensions, including angina frequency (p < 0.001), compared to placebo-treated patients.
A small proportion of non-Caucasians was included in the controlled clinical studies; therefore, no conclusions can be drawn regarding the effect and safety in non-Caucasians.
In a phase 3, double-blind, placebo-controlled, event-driven trial (RIVER-PCI) in 2604 patients aged ≥18 years with a history of chronic angina and incomplete revascularisation after percutaneous coronary intervention (PCI) patients were up-titrated to 1000 mg twice daily (dosage not approved in the current SmPC). No significant difference occurred in the composite primary endpoint (time to first occurrence of ischaemia-driven revascularisation or ischaemia-driven hospitalisation without revascularisation) in the ranolazine group (26.2%) versus the placebo group (28.3%), hazard ratio 0.95, 95% CI 0.82-1.10 p= 0.48. The risk of all cause mortality, CV death or major adverse cardiovascular events (MACE) and heart failure hospitalisation was similar between treatment groups in the overall population; however, MACE were reported more frequently in patients ≥ 75 years treated with ranolazine compared with placebo (17.0% vs 11.3%, respectively); in addition there was a numerical increase in all cause mortality in patients ≥ 75 years (9.2% vs. 5.1%, p = 0.074).
Pharmacokinetics: After oral administration of Ranexa, peak plasma concentrations (Cmax) are typically observed between 2 and 6 hours. Steady state is generally achieved within 3 days of twice-daily dosing.
Absorption: The mean absolute bioavailability of ranolazine after oral administration of immediate-release ranolazine tablets ranged from 35-50%, with large inter-individual variability. Ranexa exposure increases more than in proportion to dose. There was a 2.5- to 3-fold increase in steady-state AUC as the dose was increased from 500 mg to 1000 mg twice daily. In a pharmacokinetic study in healthy volunteers, steady-state Cmax was, on average, approximately 1770 (SD 1040) ng/ml, and steady-state AUC0-12 was, on average, 13,700 (SD 8290) ng x h/ml following a dose of 500 mg twice daily. Food does not affect the rate and extent of absorption of ranolazine.
Distribution: Approximately 62% of ranolazine is bound to plasma proteins, mainly alpha-1 acid glycoprotein and weakly to albumin. The mean steady-state volume of distribution (Vss) is about 180 l.
Elimination: Ranolazine is eliminated primarily by metabolism. Less than 5% of the dose is excreted unchanged in the urine and faeces. Following oral administration of a single 500 mg dose of [14C]-ranolazine is dose-dependent, decreasing with increased dose. The elimination half-life is about 2-3 hours after intravenous administration. The terminal half-life at steady state after oral administration of ranolazine is about 7 hours, due to the absorption rate-limited elimination.
Biotransformation: Ranolazine undergoes rapid and extensive metabolism. In healthy young adults, ranolazine accounts for approximately 13% of the radioactivity in plasma following a single oral 500 mg dose of [14C]-ranolazine. A large number of metabolites has been identified in human plasma (47 metabolites), urine (> 100 metabolites), and faeces (25 metabolites). Fourteen primary pathways have been identified of which O-demethylation and N-dealkylation are the most important. In vitro studies using human liver microsomes indicate that ranolazine is metabolised primarily by CYP3A4, but also by CYP2D6. At 500 mg twice daily, subjects lacking CYP2D6 activity (poor metabolisers, PM) had 62% higher AUC than subjects with CYP2D6 metabolising capacity (extensive metabolisers, EM). The corresponding difference at the 1000 mg twice-daily dose was 25%.
Special populations: The influence of various factors on the pharmacokinetics of ranolazine was assessed in a population pharmacokinetic evaluation in 928 angina patients and healthy subjects.
Gender effects: Gender had no clinically relevant effect on pharmacokinetic parameters.
Elderly patients: Age alone had no clinically relevant effect on pharmacokinetic parameters.
However, the elderly may have increased ranolazine exposure due to age-related decrease in renal function.
Body weight: Compared to subjects weighing 70 kg, exposure was estimated to be about 1.4-fold higher in subjects weighing 40 kg.
CHF: CHF NYHA Class III and IV were estimated to have about 1.3-fold higher plasma concentrations.
Renal impairment: In a study evaluating the influence of renal function on ranolazine pharmacokinetics, ranolazine AUC was on average 1.7- to 2-fold higher in subjects with mild, moderate, and severe renal impairment compared with subjects with normal renal function. There was a large inter-individual variability in AUC in subjects with renal impairment.
The AUC of metabolites increased with decreased renal function. The AUC of one pharmacologically active ranolazine metabolite was 5-fold increased in patients with severe renal impairment. In the population pharmacokinetic analysis, a 1.2-fold increase in ranolazine exposure was estimated in subjects with moderate impairment (creatinine clearance 40 ml/min). In subjects with severe renal impairment (creatinine clearance 10-30 ml/min), a 1.3- to 1.8-fold increase in ranolazine exposure was estimated.
The influence of dialysis on the pharmacokinetics of ranolazine has not been evaluated.
Hepatic impairment: The pharmacokinetics of ranolazine have been evaluated in patients with mild or moderate hepatic impairment. There are no data in patients with severe hepatic impairment. Ranolazine AUC was unaffected in patients with mild hepatic impairment but increased 1.8-fold in patients with moderate impairment. QT prolongation was more pronounced in these patients.
Paediatric population: The pharmacokinetic parameters of ranolazine have not been studied in the paediatric population (< 18 years).
Toxicology: Preclinical safety data: Adverse reactions not observed in clinical studies, but seen in animals at levels similar to clinical exposure, were as follows: Ranolazine was associated with convulsions and increased mortality in rats and dogs at plasma concentrations approximately 3-fold higher than at the proposed maximum clinical dose.
Chronic toxicity studies in rats indicated that treatment was associated with adrenal changes at exposures slightly greater than those seen in clinical patients. This effect is associated with increased plasma cholesterol concentrations. No similar changes have been identified in humans. No effect on the adreno-cortical axis was noted in humans.
In long-term carcinogenicity studies at doses of ranolazine up to 50 mg/kg/day (150 mg/m2/day) in mice and 150 mg/kg/day (900 mg/m2/day) in rats, no relevant increases in the incidence of any tumour types were seen. These doses are equivalent to 0.1 and 0.8 times, respectively, the maximum recommended human dose of 2 grams on a mg/m2 basis, and represent the maximum tolerated doses in these species.
Signs of embryonal and maternal toxicity, but not teratogenicity, were seen at doses of ranolazine up to 400 mg/kg/day (2400 mg/m2/day) in rats and 150 mg/kg/day (1800 mg/m2/day) in rabbits. These doses represent 2.7 and 2 times, respectively, the maximum recommended human dose.
Animal studies do not indicate direct or indirect harmful effects of ranolazine with respect to male or female fertility.
