Cilostazol for Secondary Prevention of Stroke: Should the Guidelines Perhaps Be Extended?

IC Regimen: Delaying Resistance to Lorlatinib in ALK Driven Cancers by Adding Repurposed Itraconazole and Cilostazol

Lorlatinib is a pharmaceutical ALK kinase inhibitor used to treat ALK driven non-small cell lung cancers. This paper analyses the intersection of past published data on the physiological consequences of two unrelated drugs from general medical practice-itraconazole and cilostazol-with the pathophysiology of ALK positive non-small cell lung cancer. A conclusion from that data analysis is that adding itraconazole and cilostazol may make lorlatinib more effective. Itraconazole, although marketed worldwide as a generic antifungal drug, also inhibits Hedgehog signaling, Wnt signaling, hepatic CYP3A4, and the p-gp efflux pump. Cilostazol, marketed worldwide as a generic thrombosis preventative drug, acts by inhibiting phosphodiesterase 3, and, by so doing, lowers platelets' adhesion, thereby partially depriving malignant cells of the many tumor trophic growth factors supplied by platelets. Itraconazole may enhance lorlatinib effectiveness by (i) reducing or stopping a Hedgehog-ALK amplifying feedback loop, by (ii) increasing lorlatinib's brain levels by p-gp inhibition, and by (iii) inhibiting growth drive from Wnt signaling. Cilostazol, surprisingly, carries minimal bleeding risk, lower than that of aspirin. Risk/benefit assessment of the combination of metastatic ALK positive lung cancer being a low-survival disease with the predicted safety of itraconazole-cilostazol augmentation of lorlatinib favors a trial of this drug trio in ALK positive lung cancer.

The effect of cilostazol on late outcomes after endovascular treatment for occlusive femoropopliteal disease

OBJECTIVE

Restenosis and late occlusion remain a significant problem for endovascular treatment of peripheral artery disease. This meta-analysis aims to evaluate the effect of cilostazol on late outcomes after endovascular repair of occlusive femoropopliteal disease.

METHODS

A systematic literature review was conducted conforming to established criteria to identify articles published up to September 2023 evaluating late outcomes after endovascular treatment for atherosclerotic femoropopliteal disease. Eligible studies should compare outcomes between patients treated with cilostazol and patients not treated with cilostazol. Both prospective and retrospective studies were eligible. Late outcomes included primary patency (PP), restenosis, target lesion revascularization (TLR), and major amputation during follow-up.

RESULTS

Overall, 10 clinical studies were identified for analysis including 4721 patients (1831 with cilostazol vs 2890 without cilostazol) that were treated for 5703 lesions (2235 with cilostazol vs 3468 without cilostazol). All studies were performed in Japan. Mean follow-up was 24.1 ± 12.5 months. Cilostazol was associated with a lower risk for restenosis (pooled odds ratio [OR], 0.503; 95% confidence interval [CI], 0.383-0.660; P < .0001). However, no association was found between cilostazol and TLR (pooled OR, 0.918; 95% CI, 0.300-2.812; P = .881) as well as major amputation (pooled OR, 1.512; 95% CI, 0.734-3.116; P = .263). Regarding primary patency, cilostazol was associated with a higher 12-month PP (OR, 3.047; 95% CI, 1.168-7.946; P = .023), and a higher 36-month PP (OR, 1.616; 95% CI, 1.412-1.850; P < .0001). No association was found between cilostazol and mortality during follow-up (pooled OR, .755; 95% CI, 0.293-1.946; P = .561).

CONCLUSIONS

Cilostazol seems to have a positive effect on 1- to 3-year PP and restenosis rates among patients treated endovascularly for atherosclerotic femoropopliteal disease. A positive effect on TLR and amputation risk was not verified in this review.

Cilostazol induces vasorelaxation through the activation of the eNOS/NO/cGMP pathway, prostanoids, AMPK, PKC, potassium channels, and calcium channels

OBJECTIVE

This study aimed to investigate vasoactive effect mechanisms of cilostazol in rat thoracic aorta.

MATERIALS AND METHODS

The vessel rings prepared from the thoracic aortas of the male rats were placed in the chambers of the isolated tissue bath system. The resting tone was adjusted to 1 g. Following the equilibration phase, potassium chloride or phenylephrine was used to contract the vessel rings. When achieving a steady contraction, cilostazol was applied cumulatively (10-8-10-4 M). In the presence of potassium channel blockers or signaling pathway inhibitors, the same experimental procedure was performed.

RESULTS

Cilostazol exhibited a significant vasorelaxant effect in a concentration-dependent manner (pD2: 5.94 ± 0.94) (p < .001). The vasorelaxant effect level of cilostazol was significantly reduced by the endothelial nitric oxide synthase inhibitor L-NAME (10-4 M), soluble guanylate cyclase inhibitor methylene blue (10 µM), cyclooxygenase 1/2 inhibitor indomethacin (5 µM), adenosine monophosphate-activated protein kinase inhibitor compound C (10 µM), non-selective potassium channel blocker tetraethylammonium chloride (10 mM), large-conductance calcium-activated potassium channel blocker iberiotoxin (20 nM), voltage-gated potassium channel blocker 4-Aminopyridine (1 mM), and inward-rectifier potassium channel blocker BaCl2 (30 µM) (p < .001). Moreover, incubation of cilostazol (10-4 M) significantly reduced caffeine (10 mM), cyclopiazonic acid (10 µM), and phorbol 12-myristate 13-acetate-induced (100 µM) vascular contractions (p < .001).

CONCLUSIONS

In the rat thoracic aorta, the vasodilator action level of cilostazol is quite noticeable. The vasorelaxant effects of cilostazol are mediated by the eNOS/NO/cGMP pathway, prostanoids, AMPK pathway, PKC, potassium channels, and calcium channels.

Pharmacodynamic of cilostazol for anti-altitude hypoxia

OBJECTIVES

The plateau environment is characterized by low oxygen partial pressure, leading to the reduction of oxygen carrying capacity in alveoli and the reduction of available oxygen in tissues, and thus causing tissue damage. Cilostazol is a phosphodiesterase III inhibitor that has been reported to increase the oxygen release of hemoglobin (Hb) in tissues. This study aims to explore the anti-hypoxic activity of cilostazol and its anti-hypoxic effect.

METHODS

A total of 40 male BALB/C mice were randomly divided into a low-dose cilostazol (6.5 mg/kg) group, a medium-dose (13 mg/kg) group, a high-dose (26 mg/kg) group, and a control group. The atmospheric airtight hypoxia experiment was used to investigate the anti-hypoxic activity of cilostazol and to screen the optimal dosage. Twenty-four male Wistar rats were randomly divided into a normoxia control group, a hypoxia model group, an acetazolamide (22.33 mg/kg) group, and a cilostazol (9 mg/kg) group. After 3 days of hypoxia in the 4 010 m high altitude, blood from the abdominal aorta was collected to determine blood gas indicators, the levels of IL-6 and TNF-α in plasma were determined by enzyme-linked immunosorbent assay, and the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutataione (GSH) were measured. The degree of pathological damage for rat tissues was observed with HE staining.

RESULTS

Compared with the control group, the survival time of mice in the low, medium, and high dose group of cilostazol was significantly prolonged, and the survival time of mice in the medium dose group was the longest, with an extension rate at 29.34%, so the medium dose was the best dose. Compared with the hypoxia model group, the P50 (oxygen partial pressure at Hb oxygen saturation of 50%) value of rats in the cilostazol group was significantly increased by 1.03%; Hb and Hct were significantly reduced by 8.46% and 8.43%, and the levels of IL-6 and TNF-α in plasma were reduced by 50.65% and 30.77%. The MDA contents in heart, brain, lung, liver, and kidney tissues were reduced by 37.12%, 29.55%, 25.00%, 39.34%, and 21.47%, respectively. The SOD activities were increased by 94.93%, 9.14%, 9.42%, 13.29%, and 20.80%, respectively. The GSH contents were increased by 95.24%, 28.62%, 28.57%, 20.80%, and 44.00%, respectively. The results of HE staining showed that compared with the hypoxia model group, cilostazol significantly improved the damage of heart, lung, and kidney tissues in rats after hypoxia.

CONCLUSIONS

Cilostazol can significantly improve the oxidative stress and inflammatory reaction caused by rapid altitude hypoxia, and it has a significant protective effect on tissue damage caused by hypoxia, suggesting that it has obvious anti-hypoxic activity.

Cilostazol: a Review of Basic Mechanisms and Clinical Uses

Primarily used in the treatment of intermittent claudication, cilostazol is a 2-oxyquinolone derivative that works through the inhibition of phosphodiesterase III and related increases in cyclic adenosine monophosphate (cAMP) levels. However, cilostazol has been implicated in a number of other basic pathways including the inhibition of adenosine reuptake, the inhibition of multidrug resistance protein 4, among others. It has been observed to exhibit antiplatelet, antiproliferative, vasodilatory, and ischemic-reperfusion protective properties. As such, cilostazol has been investigated for clinical use in a variety of settings including intermittent claudication, as an adjunctive for reduction of restenosis after coronary and peripheral endovascular interventions, and in the prevention of secondary stroke, although its widespread implementation for indications other than intermittent claudication has been limited by relatively modest effect sizes and lack of studies in western populations. In this review, we highlight the pleiotropic effects of cilostazol and the evidence for its clinical use.

Refractory cerebral infarction in a child with an ACTA2 mutation

INTRODUCTIONS

A specific mutation in the ACTA2 gene is known to cause multisystemic smooth muscle dysfunction syndrome, which is associated with cerebrovascular diseases and various organ disorders. Cerebral infarctions resulting from severe vasculopathy can be refractory; however, there are no previous reports describing the detailed clinical course of recurrent cerebral infarctions due to an ACTA2 mutation. Herein, we report a patient with an ACTA2 mutation who experienced multiple refractory cerebral infarctions in early childhood.

PATIENT DESCRIPTION

The patient was aged 1 year and 5 months at her first episode of cerebral infarction. Arteriopathy due to an ACTA2 mutation was diagnosed based on the characteristic cerebrovascular findings and abnormal physical findings, such as bilateral dilated pupils. Bilateral encephaloduroarteriosynangiosis and encephalogaleosynangiosis were performed after the first episode. Because the cerebral infarctions recurred postoperatively, administration of cilostazol followed by bosentan was started. However, despite these treatments she experienced seven cerebral infarctions by age 2 years and 6 months.

INTERPRETATION

Cerebral infarctions in patients with a specific ACTA2 mutation can occur even in early childhood, recur frequently, and cause severe motor and cognitive impairment. Physicians should be highly aware of this disease and be ready to provide the medical and surgical interventions necessary to minimize the disabling sequelae.

Treatment Approaches to Lacunar Stroke

Lacunar strokes are appropriately named for their ability to cavitate and form ponds or "little lakes" (Latin: lacune -ae meaning pond or pit is a diminutive form of lacus meaning lake). They account for a substantial proportion of both symptomatic and asymptomatic ischemic strokes. In recent years, there have been several advances in the management of large vessel occlusions. New therapies such as non-vitamin K antagonist oral anticoagulants and left atrial appendage closure have recently been developed to improve stroke prevention in atrial fibrillation; however, the treatment of small vessel disease-related strokes lags frustratingly behind. Since Fisher characterized the lacunar syndromes and associated infarcts in the late 1960s, there have been no therapies specifically targeting lacunar stroke. Unfortunately, many therapeutic agents used for the treatment of ischemic stroke in general offer only a modest benefit in reducing recurrent stroke while adding to the risk of intracerebral hemorrhage and systemic bleeding. Escalation of antithrombotic treatments beyond standard single antiplatelet agents has not been effective in long-term lacunar stroke prevention efforts, unequivocally increasing intracerebral hemorrhage risk without providing a significant benefit. In this review, we critically review the available treatments for lacunar stroke based on evidence from clinical trials. For several of the major drugs, we summarize the adverse effects in the context of this unique patient population. We also discuss the role of neuroprotective therapies and neural repair strategies as they may relate to recovery from lacunar stroke.

Effect of Cilostazol on Incident Dementia in Elderly Men and Women with Ischemic Heart Disease

BACKGROUND

Ischemic heart disease (IHD) is associated with cognitive decline and may contribute to an increased risk of dementia.

OBJECTIVE

The goal of the present study was to investigate whether cilostazol use is associated with a lower risk of incident dementia in Asian patients with IHD, and whether these effects differed based on sex.

METHODS

This retrospective cohort study was performed using the Korean National Insurance Claim Data of the Health Insurance Review and Assessment Service; the duration of the study was from January 1, 2007 to December 31, 2015. The study group comprised 66,225 patients with IHD, aged >65 years, who had received cilostazol. Age- and sex-matched IHD patients without cilostazol exposure were selected as the control group. The risk of dementia was compared between the cilostazol and control groups.

RESULTS

Compared to the control group, total cilostazol users had a marginally significant lower risk of incident dementia. After stratification by sex, the reducing effect of cilostazol on incident dementia was significant in female participants, but not in male participants. Female patients who had cilostazol for over 2 years showed a clinically meaningful preventive effect (HR, 0.85; 95% CI, 0.82-0.88).

CONCLUSIONS

This study suggested that cilostazol treatment may reduce the risk of incident dementia in Korean patients with IHD. Its beneficial effect was remarkably significant in female patients who received cilostazol for over a 2-year period.

Cilostazol for treatment of cerebral infarction

INTRODUCTION

Stroke not only causes critical disability and death but is also a cause of anxiety with the possibility of secondary cardiovascular events including secondary ischemic stroke. Indeed, patients with a history of previous stroke have a high rate of stroke recurrence, indicating the clinical importance of secondary stroke prevention. Area of covered: This review provides an overview of the pooled evidence for cilostazol's use in the management of secondary stroke prevention. Among the various antiplatelet agents that are available, aspirin is the most frequently used agent worldwide for the prevention of secondary stroke. Cilostazol, a selective phosphodiesterase (PDE) 3A inhibitor, is used worldwide for the treatment of patients with intermittent claudication. However, in Asia, cilostazol is recommended and used in practice for secondary stroke prevention. Expert opinion: The authors believe that cilostazol could be used for secondary stroke prevention not only in Asia but worldwide. However, further randomized trials on cilostazol are needed, especially in the US and Europe to better support its case.

Critical evaluation on proper antithrombotic treatment in different groups of patients undergoing vascular surgery

Antithrombotic treatment including anticoagulants and antiplatelets has evolved during the last decades, and several recommendations have been included in the latest guidelines regarding the proper management of patients undergoing vascular surgery. However, there are significant differences compared to older recommendations, and indications vary among patients with peripheral artery disease, carotid disease, and abdominal aortic aneurysm. In this mini review, we critically evaluate all these data to produce useful conclusions for everyday clinical practice.