Effects of a new metabolic modulator, ranolazine, on exercise tolerance in angina pectoris patients treated with beta-blocker or diltiazem

Ranolazine (RS 43285) is a new piperazine derivative with anti-ischemic properties attributed to a modulation of myocardial metabolism. Its antianginal action was assessed in 104 patients recruited in a double-blind, crossover, randomized study comparing placebo with a single dose of ranolazine (10, 60, 120, and 240 mg). All patients had chronic stable angina pectoris and remained symptomatic (at least 0.1 mV ST-segment depression and angina during prestudy exercise testing) despite treatment with a beta-blocker or with diltiazem. No significant effects of ranolazine on exercise duration or time to angina were observed after the dose of 10, 60, and 120 mg. After the 240 mg dose, however, significant improvement in exercise duration (+13.1% in the combined group, two-tailed p = 0.002; +14.3% in the beta-blocker group, p = 0.009; +11.9% in the diltiazem group, p = 0.06), in time to angina (+56.8 s, p = 0.008), and in time to 1 mm ST-segment depression was observed. The cumulative proportion of patients who improved their time to angina by at least 30 s above placebo were 25, 42, 50, and 72% with the doses of 10, 60, 120, and 240 mg, respectively. Sixty-seven percent of the patients with ranolazine plasma levels above 500 ng/ml improved their time to angina against 40% at plasma levels below 500 ng/ml and summed ST-segment depression during exercise and recovery was also significantly reduced at these plasma concentrations. Both heart rate and arterial pressure at rest and at peak exercise were unchanged after ranolazine, 240 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Ranolazine--a new drug with beneficial effects on renal preservation

Ranolazine is a new drug with a novel mode of action as a metabolic modulator and membrane stabilizer. In this prospective randomized double-blind trial, a porcine model of renal autotransplantation was used to assess the effects of this drug during preservation and reperfusion of kidneys cold-stored for 24 hr in phosphate-buffered sucrose (PBS140). Three groups of 10 animals were compared: a Placebo group (placebo given intravenously to the animal before nephrectomy, added to the preservation solution, and given again to the animal during reperfusion); a Storage group (Ranolazine before and during storage, placebo during reperfusion); and a Reperfusion group (placebo before and during storage, Ranolazine during reperfusion). Detailed analysis of posttransplant renal function was carried out over a 14-day follow-up period. There were 7 deaths with primary nonfunction: 2 Placebo, 1 Storage, 4 Reperfusion. Analysis of the whole group and separate analysis of the survivors demonstrated significantly improved glomerular (P less than 0.05), tubular (P less than 0.05), and loop of Henle (P less than 0.05) function in the Storage group. The results of this study clearly demonstrate the beneficial effects of Ranolazine during the storage phase of porcine renal preservation, and further investigation of this drug is warranted.

Ranolazine (RS-43285): a preliminary study of a new anti-anginal agent with selective effect on ischaemic myocardium

Ranolazine (RS-43285) has been shown to possess significant anti-ischaemic properties in a canine model of reversible myocardial ischaemia. The clinical efficacy of this new agent was assessed by a single blind, placebo controlled study of 14 patients with chronic stable angina. A 2 week placebo phase was followed by therapy with 30 mg and 60 mg of ranolazine tid for 2 weeks each. Graded, symptom limited treadmill exercise tests were performed at the end of each phase, 1.5 h (AM) and 7 h (PM) after the morning dose. An additional exercise test 1.5 h after the first dose of 30 mg was included to assess the acute dose response. In the AM study, the mean exercise time increased from 6.9 min (placebo) to 7.8 min after the first dose of 30 mg and to 8.2 min and 8.5 min respectively at the end of 30 mg and 60 mg phases. In the PM study, exercise time improved from 6.5 min (placebo) to 8.2 min and 7.8 min respectively at the end of 30 mg and 60 mg phases. The time to onset of angina showed a similar improvement. No significant changes were observed in the resting and peak exercise heart rates and blood pressure. This preliminary study suggests that ranolazine may significantly prolong exercise time in patients with stable coronary artery disease without altering heart rates and blood pressure.

Prevention of myocardial enzyme release by ranolazine in a primate model of ischaemia with reperfusion

In control anaesthetized baboons subjected to 30 min occlusion of the left anterior descending coronary artery, followed by 5.5 h reperfusion, total plasma levels for creatine kinase (CK) and lactate dehydrogenase (LDH) were markedly elevated in a time-related manner. In a second group of baboons pretreated 10 min prior to ischaemia with ranolazine [(+/-)-N-(2,6-dimethyl-phenyl)-4[2-hydroxy-3-(2-methoxyphenoxy)propyl]-1 - piperazine acetamide dihydrochloride; RS-43285-193] at 500 micrograms kg-1 i.v., followed by continuous infusion of 50 micrograms kg-1 min-1, neither enzyme was significantly elevated at any time point. Similarly, serum levels of the cardiospecific isoenzyme CK2 were 8 fold greater in the controls than in the ranolazine-treated animals at 6 h. The results indicate that ranolazine pretreatment abolished cardiac enzyme release over a 5.5 h reperfusion period, indicating a potential protective effect.

The effects of the novel anti-anginal compound RS 43285 on myocardial conduction in the anaesthetized dog

1. A pentobarbitone-anaesthetized canine model of myocardial conduction was developed to evaluate drug effects on intra-atrial (I-A), intra-ventricular (I-V) and atrioventricular (A-V) conduction parameters, both at rest and during electrical pacing of the right atrium or ventricle. Drug effects on the ability of the sino-atrial (SA) node to re-establish sinus rhythm on switching off electrical pacing were also considered. The effects of the novel anti-anginal compound RS 43285-193 ((+/-)-N-(2,6-dimethyl-phenyl)-4[2-hydroxy-3-(2-methoxyphenoxy)propyl] -1-piperazine acetamide dihydrochloride) were compared to those of the standard anti-anginal compounds nicardipine, nifedipine and verapamil. 2. In the dose range 15-7000 micrograms kg-1, RS 43285 had no significant effects on I-A, I-V or A-V conduction either at rest or during electrical pacing and did not affect the re-establishment of sinus rhythm. 3. Nicardipine had no effects on conduction parameters at resting heart rate. There were no effects on I-A or I-V conduction on electrical pacing but A-V conduction was increased at 200-500 micrograms kg-1 (with a 2:1 A-V conduction block in two out of six dogs); this was accompanied by a prolongation of the interval to reversion of sinus rhythm. 4. Nifedipine had no significant effects on I-A or I-V conduction but significantly prolonged A-V conduction at 1000 micrograms kg-1 and this dose also increased the interval to SA node recovery. 5. Verapamil did not effect I-A or I-V conduction. However, A-V conduction was affected with a significant prolongation occurring at resting heart rate at 100-400 Atg kg-' and a 2:1 A-V block in one dog at rest. During right atrial pacing verapamil significantly increased A-V conduction at 50- 400 fig kg-'. All dogs exhibited a 2:1 A-V conduction block at the highest frequency at 400 jig kg-'.