Efficacy and Safety of Ranolazine in Diabetic Patients: A Systematic Review and Meta-analysis

Improvement of Vascular Insulin Sensitivity by Ranolazine

Ranolazine (RN) is a drug used in the treatment of chronic coronary ischemia. Different clinical trials have shown that RN behaves as an anti-diabetic drug by lowering blood glucose and glycosylated hemoglobin (HbA1c) levels. However, RN has not been shown to improve insulin (IN) sensitivity. Our study investigates the possible facilitating effects of RN on the actions of IN in the rabbit aorta. IN induced vasodilation of the abdominal aorta in a concentration-dependent manner, and this dilatory effect was due to the phosphorylation of endothelial nitric oxide synthase (eNOS) and the formation of nitric oxide (NO). On the other hand, IN facilitated the vasodilator effects of acetylcholine but not the vasodilation induced by sodium nitroprusside. RN facilitated all the vasodilatory effects of IN. In addition, IN decreased the vasoconstrictor effects of adrenergic nerve stimulation and exogenous noradrenaline. Both effects were in turn facilitated by RN. The joint effect of RN with IN induced a significant increase in the ratio of p-eNOS/eNOS and pAKT/AKT. In conclusion, RN facilitated the vasodilator effects of IN, both direct and induced, on the adrenergic system. Therefore, RN increases vascular sensitivity to IN, thus decreasing tissue resistance to the hormone, a key mechanism in the development of type II diabetes.

Facilitation of Insulin Effects by Ranolazine in Astrocytes in Primary Culture

Ranolazine (Rn) is a drug used to treat persistent chronic coronary ischemia. It has also been shown to have therapeutic benefits on the central nervous system and an anti-diabetic effect by lowering blood glucose levels; however, no effects of Rn on cellular sensitivity to insulin (Ins) have been demonstrated yet. The present study aimed to investigate the permissive effects of Rn on the actions of Ins in astrocytes in primary culture. Ins (10−8 M), Rn (10−6 M), and Ins + Rn (10−8 M and 10−6 M, respectively) were added to astrocytes for 24 h. In comparison to control cells, Rn and/or Ins caused modifications in cell viability and proliferation. Rn increased protein expression of Cu/Zn-SOD and the pro-inflammatory protein COX-2 was upregulated by Ins. On the contrary, no significant changes were found in the protein expression of NF-κB and IκB. The presence of Rn produced an increase in p-ERK protein and a significant decrease in COX-2 protein expression. Furthermore, Rn significantly increased the effects of Ins on the expression of p-AKT, p-eNOS, p-ERK, Mn-SOD, and PPAR-γ. In addition, Rn + Ins produced a significant decrease in COX-2 expression. In conclusion, Rn facilitated the effects of insulin on the p-AKT, p-eNOS, p-ERK, Mn-SOD, and PPAR-γ signaling pathways, as well as on the anti-inflammatory and antioxidant effects of the hormone.

Ranolazine: An Old Drug with Emerging Potential; Lessons from Pre-Clinical and Clinical Investigations for Possible Repositioning

Ischemic heart disease is a significant public health problem with high mortality and morbidity. Extensive scientific investigations from basic sciences to clinics revealed multilevel alterations from metabolic imbalance, altered electrophysiology, and defective Ca²⁺/Na⁺ homeostasis leading to lethal arrhythmias. Despite the recent identification of numerous molecular targets with potential therapeutic interest, a pragmatic observation on the current pharmacological R&D output confirms the lack of new therapeutic offers to patients. By contrast, from recent trials, molecules initially developed for other fields of application have shown cardiovascular benefits, as illustrated with some anti-diabetic agents, regardless of the presence or absence of diabetes, emphasizing the clear advantage of “old” drug repositioning. Ranolazine is approved as an antianginal agent and has a favorable overall safety profile. This drug, developed initially as a metabolic modulator, was also identified as an inhibitor of the cardiac late Na⁺ current, although it also blocks other ionic currents, including the hERG/Ikr K⁺ current. The latter actions have been involved in this drug’s antiarrhythmic effects, both on supraventricular and ventricular arrhythmias (VA). However, despite initial enthusiasm and promising development in the cardiovascular field, ranolazine is only authorized as a second-line treatment in patients with chronic angina pectoris, notwithstanding its antiarrhythmic properties. A plausible reason for this is the apparent difficulty in linking the clinical benefits to the multiple molecular actions of this drug. Here, we review ranolazine’s experimental and clinical knowledge on cardiac metabolism and arrhythmias. We also highlight advances in understanding novel effects on neurons, the vascular system, skeletal muscles, blood sugar control, and cancer, which may open the way to reposition this “old” drug alone or in combination with other medications.

Long-Term (3 Years) Outcomes of Ranolazine Therapy for Refractory Angina Pectoris (from the Ranolazine Refractory Registry)

Ranolazine is approved for patients with chronic stable angina but has not been formally studied in patients with refractory angina pectoris (RAP). Patients with RAP have limited therapeutic options and significant limitations in their quality of life. The Ranolazine Refractory Angina Registry was designed to evaluate the safety, tolerability, and effectiveness of ranolazine in RAP patients in order to expand treatment options for this challenging patient population. Using an extensive prospective database, we enrolled 158 consecutive patients evaluated in a dedicated RAP clinic. Angina class, medications, major adverse cardiac events including death, myocardial infarction, and revascularization were obtained at 12, 24, and 36 months. At 3 years, 95 (60%) patients remained on ranolazine. A ≥2 class improvement in angina was seen in 48% (38 of 80 patients with known Canadian Cardiovascular Society class) of those who remained on ranolazine. Discontinuation due to side effects, ineffectiveness, cost, and progression of disease were the principle reasons for discontinuation, but primarily occurred within the first year. In conclusion, ranolazine is an effective antianginal therapy at 3-year follow-up in patients with RAP and may reduce cardiac readmission.