Ranolazine-induced myopathy in a patient on chronic statin therapy

Prevalence and predictors of clinically significant statin-drug interactions among Yemeni patients taking statins for primary and secondary prevention of cardiovascular disease

BACKGROUND

Statins are extensively used in clinical practice for the primary and secondary prevention of cardiovascular diseases. Statins are usually taken in combination with other medications. This may increase the risk of statin-drug interactions. The study aimed to evaluate the prevalence, patterns, and predictors of clinically significant statin-drug interactions among patients on statin therapy.

MATERIAL AND METHODS

A cross-sectional study was conducted at the cardiology, endocrine, and internal medicine outpatient clinics in four tertiary care hospitals in Sana'a, Yemen. Lexicomp Drug Interaction database was used to analyze the prescriptions for potential statin-drug interactions. Binary and multivariable logistic regression were utilized for analysis.

RESULTS

Of the total number of patients (634), 114 individuals (18%) had a total of 122 statin-drug interactions. According to Lexicomp risk classification, 102 (83.6%) DDIs were class C (monitor therapy), 19 (15.6%) were class D (therapy modification), and only one (0.8%) class X (avoid combination). Simvastatin use was significantly associated with the presence of category D and X DDIs (15.9% vs. 1.6%, p < .001). Polypharmacy (OR = 2.571, p < .001) and having ≥3 comorbidities (OR = 2.512, p < .001) were the only variables associated with the presence of statin-drug interactions (C, D, and/or X).

CONCLUSION

Patients with polypharmacy and those with three or more comorbidities had a higher risk for statin-drug interactions. Therefore, routine screening by physicians and pharmacists for potential interactions should occur before prescribing or dispensing any medication to avoid clinically significant statin-drug interactions.

Ranolazine-induced lipid storage myopathy presenting with respiratory failure and head drop

Ranolazine is an anti-ischemic drug often used along with statins in patients with ischemic heart disease. Ranolazine-induced proximal myopathy or rhabdomyolysis have been rarely reported, but toxic effects of statins could not be completely ruled out in those cases. We report a 68-year-old man with ranolazine-induced myopathy who presented with respiratory insufficiency and head drop. Creatine kinase level was normal. The Patient continued to worsen despite statin cessation but markedly improved after stopping ranolazine. Muscle biopsy showed excessive lipid accumulation predominantly in type 1 myofibers. The precise mechanism of toxicity is not clear. Treating physicians should be aware of this rare but potentially debilitating adverse effect of ranolazine. Prognosis is good upon discontinuation of the offending drug.

Neurological complications of cardiovascular drugs

Cardiovascular drugs are used to treat arterial hypertension, hyperlipidemia, arrhythmias, heart failure, and coronary artery disease. They also include antiplatelet and anticoagulant drugs that are essential for prevention of cardiogenic embolism. Most neurologic complications of the cardiovascular drugs are minor or transient and are far outweighed by the anticipated benefits of treatment. Other neurologic complications are more serious and require early recognition and management. Overtreatment of arterial hypertension may cause lightheadedness or fatigue but often responds readily to dose adjustment or an alternative drug. Other drug complications may be more troublesome as in myalgia associated with statins or headache associated with vasodilators. The recognized bleeding risk of the antithrombotics requires careful calculation of risk/benefit ratios for individual patients. Many neurologic complications of cardiovascular drugs are well documented in clinical trials with known frequency and severity, but others are rare and recognized only in isolated case reports or small case series. This chapter draws on both sources to report the adverse effects on muscle, nerve, and brain associated with commonly used cardiovascular drugs.

Ranolazine: Electrophysiologic Effect, Efficacy, and Safety in Patients with Cardiac Arrhythmias

Ranolazine is currently approved as an antianginal agent in patients with chronic angina (class IIA). Ranolazine exhibits antiarrhythmic effects that are related to its multichannel blocking effect, predominantly inhibition of late sodium (late INa) current and the rapid potassium rectifier current (IKr), as well as ICa, late ICa, and INa-Ca. It also suppresses the early and delayed after depolarizations. Ranolazine is effective in the suppression of atrial and ventricular arrhythmias (off-label use) without significant proarrhythmic effect. Currently, ongoing trials are evaluating the efficacy and safety of ranolazine in patients with cardiac arrhythmias; preliminary results suggest that ranolazine, when used alone or in combination with dronedarone, is safe and effective in reducing atrial fibrillation. Ranolazine is not currently approved by the US Food and Drug Administration as an antiarrhythmic agent.

Ranolazine in Cardiac Arrhythmia

Ranolazine utilization in the management of refractory angina has been established by multiple randomized clinical studies. However, there is growing evidence showing an evolving role in the field of cardiac arrhythmias. Multiple experimental and clinical studies have evaluated the role of ranolazine in prevention and management of atrial fibrillation, with ongoing studies on its role in ventricular arrhythmias. In this review, we will discuss the pharmacological, experimental, and clinical evidence behind ranolazine use in the management of various cardiac arrhythmias.

Myopathy during treatment with the antianginal drug ranolazine

Ranolazine is a medication indicated for treatment of chronic angina and is a partial inhibitor of the fatty acid β-oxidation. We present an adult patient who developed subacute progressive muscle weakness and exercise-induced myalgia, soon after increasing the daily dose of ranolazine, in the setting of therapy with simvastatin. CK persisted normal throughout the duration of the weakness and muscle biopsy showed a lipid storage myopathy for which no underlying genetic defect was identified. Discontinuation of both drugs resulted in clinical improvement. Although simvastatin may have contributed to the myopathy, the temporal relation between the increase in ranolazine dose and the onset of the weakness would favor ranolazine as major culprit for the weakness.