Comparison of Cilostazol and Naftidrofuryl in an Experimental Acute Ischemia-Reperfusion Model

INTRODUCTION

Naftidrofuryl and cilostazol are drugs with proven efficacy in the treatment of claudication in peripheral vascular disease. In this experimental study, we evaluated the effects of naftidrofuryl and cilostazol in ischemia-reperfusion (IR) injury on various tissues.

MATERIALS AND METHODS

40 male albino Wistar rats (8-12 weeks old, 250-350 g.) are randomly divided into 4 groups: Control (Group 1), sham (group 2), cilostazol pre-treatment (group 3), naftidrofuryl pre-treatment (group 4). During 21 days placebo is given to group 2, 12 mg/kg/day cilostazol is given to group 3, 50 mg/kg/day naftidrofuryl is given to group 4 orally. Ischemia and reperfusion are induced at the lower hind limb in Groups 2, 3 and 4. Ischemic muscle, kidney, liver, heart, brain and blood samples are obtained. The total antioxidant capacity, oxidant levels and oxidative stress index are studied for each group.

RESULTS

Both drugs have protective effects of remote organ injury following IR. Systemic effects are similar to each other, both have protective effects of IR injury. It showed no statistical significance in the total antioxidant capacity. Total oxidant levels are significantly affected by cilostazol in the heart (p < 0.01) and by naftidrofuryl in the liver (p < 0.01). The effect on oxidative stress was only significant with cilostazol on the heart (p < 0.01).

CONCLUSION

Cilostazol and naftidrofuryl had beneficial effects in all tissues against tissue damage caused by IR injury. In ischemic muscle, kidney and heart cilostazol had improved outcomes comparing to naftidrofuryl. Naftidrofuryl had benefits over cilostazol in liver tissue.

Pentoxifylline for intermittent claudication

BACKGROUND

Intermittent claudication (IC) is a symptom of peripheral arterial disease (PAD) and is associated with high morbidity and mortality. Pentoxifylline, one of many drugs used to treat IC, acts by decreasing blood viscosity, improving erythrocyte flexibility, and promoting microcirculatory flow and tissue oxygen concentration. Many studies have evaluated the efficacy of pentoxifylline in treating people with PAD, but results of these studies are variable. This is the second update of a review first published in 2012.

OBJECTIVES

To determine the efficacy of pentoxifylline in improving the walking capacity (i.e. pain-free walking distance and total (absolute, maximum) walking distance) of people with stable intermittent claudication, Fontaine stage II.

SEARCH METHODS

For this update, the Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases, and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 28 January 2020. There were no language restrictions.

SELECTION CRITERIA

We included all double-blind, randomised controlled trials (RCTs) comparing pentoxifylline versus placebo or any other pharmacological intervention in people with IC Fontaine stage II.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, assessed the included studies, matched data and resolved disagreements by discussion. Review authors assessed the methodological quality of studies using the Cochrane 'Risk of bias' tool and collected results related to the outcomes of interest, pain-free walking distance (PFWD), total walking distance (TWD), ankle-brachial pressure index (ABI), quality of life (QoL) and side effects. Comparison of studies was based on duration and dose of pentoxifylline. We used GRADE criteria to assess the certainty of the evidence.

MAIN RESULTS

We identified no new eligible studies for this update. This review includes 24 studies with 3377 participants. Seventeen studies compared pentoxifylline versus placebo. The seven remaining studies compared pentoxifylline with flunarizine (one study), aspirin (one study), Gingko biloba extract (one study), nylidrin hydrochloride (one study), prostaglandin E1 (two studies), and buflomedil and nifedipine (one study). Risk of bias for the individual studies was generally unclear because there was a lack of methodological reporting for many of the included studies, especially regarding randomisation and allocation methods. Most included studies did not provide adequate information to allow selective reporting to be judged and did not report blinding of assessors. Heterogeneity between included studies was considerable with regards to multiple variables, including duration of treatment, dose of pentoxifylline, baseline walking distance and participant characteristics; therefore, pooled analysis for comparisons which included more than one study, was not possible. Pentoxifylline compared to placebo Of 17 studies comparing pentoxifylline with placebo, 11 reported PFWD and 14 reported TWD; the difference in percentage improvement in PFWD for pentoxifylline over placebo ranged from -33.8% to 73.9% and in TWD ranged from 1.2% to 155.9%. It was not possible to pool the data of the studies because data were insufficient and findings from individual trials were unclear. Most included studies suggested a possible improvement in PFWD and TWD for pentoxifylline over placebo (both low-certainty evidence). The five studies which evaluated pre-exercise ABI comparing pentoxifylline and placebo found no evidence of a difference (moderate-certainty evidence). Two of the three studies that evaluated QoL between people who received pentoxifylline and placebo were larger studies that used validated QoL tools and generally found no evidence of a difference between groups. One small, short-term study, which did not specify which QoL tool was used, reported improved QoL in the pentoxifylline group (moderate-certainty evidence). Pentoxifylline generally was well tolerated; the most commonly reported side effects consisted of gastrointestinal symptoms such as nausea (low-certainty evidence). Certainty of the evidence from this review was low or moderate, with downgrading due to risk of bias concerns, inconsistencies between studies and the inability to evaluate imprecision because meta-analysis could not be undertaken. The seven remaining studies compared pentoxifylline with either flunarizine, aspirin, Gingko biloba extract, nylidrin hydrochloride, prostaglandin E1, or buflomedil and nifedipine; data were too limited to allow any meaningful conclusions to be made.

AUTHORS' CONCLUSIONS

There is a lack of high-certainty evidence for the effects of pentoxifylline compared to placebo, or other treatments, for IC. There is low-certainty evidence that pentoxifylline may improve PFWD and TWD compared to placebo, but no evidence of a benefit to ABI or QoL (moderate-certainty evidence). Pentoxifylline was reported to be generally well tolerated (low-certainty evidence). Given the large degree of heterogeneity between the studies, the role of pentoxifylline for people with IC Fontaine class II remains uncertain.

Sulodexide improves pain-free walking distance in patients with lower extremity peripheral arterial disease: A systematic review and meta-analysis

Peripheral arterial disease is associated with very high cardiovascular risk. The main symptom is intermittent claudication, which strongly affects the quality of life. Therefore, treatment goals in peripheral arterial disease consist of the reduction of cardiovascular events and the relief of symptoms. An increase in pain-free walking distance, evaluated based on the Initial Claudication Distance, was also a strong positive prognostic factor in patients with peripheral arterial disease. Our objective was to reassess whether sulodexide is effective in improving Initial Claudication Distance. For this, we searched the literature according to the PRISMA checklist for double blind clinical trials assessing the improvement in the Initial Claudication Distance after 90 days of standard therapeutic regimen with sulodexide in adult patients with peripheral arterial disease. We found and assessed for bias in 11 studies eligible for review and meta-analysis. Data extracted from those studies favoured the sulodexide group, showing an overall difference in Initial Claudication Distance of +68.9 (CI 95%; ± 11.9 m) at the end of treatment (p < 0.001). According to this review, sulodexide is effective in improving Initial Claudication Distance and consequently the quality of life in patients with peripheral arterial disease. Further studies are needed to assess the effects of this drug on disease progression in asymptomatic patients with peripheral arterial disease.

Pentoxifylline Regulates Plasminogen Activator Inhibitor-1 Expression and Protein Kinase A Phosphorylation in Radiation-Induced Lung Fibrosis

Purpose. Radiation-induced lung fibrosis (RILF) is a serious late complication of radiotherapy. In vitro studies have demonstrated that pentoxifylline (PTX) has suppressing effects in extracellular matrix production in fibroblasts, while the antifibrotic action of PTX alone using clinical dose is yet unexplored. Materials and Methods. We used micro-computed tomography (micro-CT) and histopathological analysis to evaluate the antifibrotic effects of PTX in a rat model of RILF. Results. Micro-CT findings showed that lung density, volume loss, and mediastinal shift are significantly increased at 16 weeks after irradiation. Simultaneously, histological analysis demonstrated thickening of alveolar walls, destruction of alveolar structures, and excessive collagen deposition in the irradiated lung. PTX treatment effectively attenuated the fibrotic changes based on both micro-CT and histopathological analyses. Western analysis also revealed increased levels of plasminogen activator inhibitor- (PAI-) 1 and fibronectin (FN) and PTX treatment reduced expression of PAI-1 and FN by restoring protein kinase A (PKA) phosphorylation but not TGF-β/Smad in both irradiated lung tissues and epithelial cells. Conclusions. Our results demonstrate the antifibrotic effect of PTX on radiation-induced lung fibrosis and its effect on modulation of PKA and PAI-1 expression as possible antifibrotic mechanisms.

Medical Therapy in Peripheral Artery Disease and Critical Limb Ischemia

OPINION STATEMENT

Peripheral artery disease (PAD) comprises atherosclerosis of the aorta and lower extremities. Many patients with PAD are asymptomatic, while others present with intermittent claudication (IC) or critical limb ischemia (CLI). Defined as rest pain or tissue loss that persists for >2 weeks, CLI represents the most severe clinical manifestation of PAD and is associated with an increased risk of limb loss and death. Patients with PAD, including those with CLI, are underdiagnosed and undertreated. In addition to smoking cessation, medical therapy with an antiplatelet agent and statin is recommended for all patients with PAD. Regular exercise has been shown to improve walking distance and quality of life in patients with symptomatic PAD and should be incorporated into each patient's treatment plan. In patients who have CLI and in those with persistent lifestyle-limiting claudication despite optimal medical therapy and an exercise program, revascularization is indicated for limb salvage and symptom relief, respectively. Consensus guidelines currently support an endovascular first approach to revascularization in the majority of cases. Surgical procedures provide an alternative to endovascular therapy in select cases.

Pentoxifylline for intermittent claudication

BACKGROUND

Intermittent claudication (IC) is a symptom of peripheral arterial disease (PAD) and is associated with high morbidity and mortality. Pentoxifylline, one of many drugs used to treat IC, acts by decreasing blood viscosity, improving erythrocyte flexibility and promoting microcirculatory flow and tissue oxygen concentration. Many studies have evaluated the efficacy of pentoxifylline in treating individuals with PAD, but results of these studies are variable. This is an update of a review first published in 2012.

OBJECTIVES

To determine the efficacy of pentoxifylline in improving the walking capacity (i.e. pain-free walking distance and total (absolute, maximum) walking distance) of individuals with stable intermittent claudication, Fontaine stage II.

SEARCH METHODS

For this update, the Cochrane Vascular Group Trials Search Co-ordinator searched the Specialised Register (last searched April 2015) and the Cochrane Register of Studies (2015, Issue 3).

SELECTION CRITERIA

All double-blind, randomised controlled trials (RCTs) comparing pentoxifylline versus placebo or any other pharmacological intervention in patients with IC Fontaine stage II.

DATA COLLECTION AND ANALYSIS

Two review authors separately assessed included studies,. matched data and resolved disagreements by discussion. Review authors assessed the methodological quality of studies by using the Cochrane 'Risk of bias' tool and collected results related to pain-free walking distance (PFWD) and total walking distance (TWD). Comparison of studies was based on duration and dose of pentoxifylline.

MAIN RESULTS

We included in this review 24 studies with 3377 participants. Seventeen studies compared pentoxifylline versus placebo. In the seven remaining studies, pentoxifylline was compared with flunarizine (one study), aspirin (one study), Gingko biloba extract (one study), nylidrin hydrochloride (one study), prostaglandin E1 (two studies) and buflomedil and nifedipine (one study). The quality of the evidence was generally low, with large variability in reported findings.. Most included studies did not report on random sequence generation and allocation concealment, did not provide adequate information to allow selective reporting to be judged and did not report blinding of assessors. Heterogeneity between included studies was considerable with regards to multiple variables, including duration of treatment, dose of pentoxifylline, baseline walking distance and participant characteristics; therefore, pooled analysis was not possible.Of 17 studies comparing pentoxifylline with placebo, 14 reported TWD and 11 reported PFWD; the difference in percentage improvement in TWD for pentoxifylline over placebo ranged from 1.2% to 155.9%, and in PFWD from -33.8% to 73.9%. Testing the statistical significance of these results generally was not possible because data were insufficient. Most included studies suggested improvement in PFWD and TWD for pentoxifylline over placebo and other treatments, but the statistical and clinical significance of findings from individual trials is unclear. Pentoxifylline generally was well tolerated; the most commonly reported side effects consisted of gastrointestinal symptoms such as nausea.

AUTHORS' CONCLUSIONS

Given the generally poor quality of published studies and the large degree of heterogeneity evident in interventions and in results, the overall benefit of pentoxifylline for patients with Fontaine class II intermittent claudication remains uncertain. Pentoxifylline was shown to be generally well tolerated.Based on total available evidence, high-quality data are currently insufficient to reveal the benefits of pentoxifylline for intermittent claudication.

Prevention of Femoropopliteal In-Stent Restenosis With Cilostazol

Severe peripheral artery disease requires revascularization to relieve life-limiting ischemic symptoms. Postrevascularization in-stent restenosis continues to be a problem after femoropopliteal procedures. Our aim was to evaluate the use of cilostazol to prevent in-stent restenosis among patients with lower extremity arterial stenting. We performed a MEDLINE and EMBASE search and reviewed the abstracts and manuscripts following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The primary efficacy outcome was patency rate after stenting. The odds ratio estimates were pooled using the Mantel–Haenszel random-effects method. We identified 524 studies, and 20 articles were fully abstracted and 4 were included in the meta-analysis. The total number of patients included was 2434. Patients in the cilostazol group had better primary patency rates after endovascular stenting than those not taking cilostazol (odds ratio: 0.55; 95% confidence interval: 0.43-0.71). The use of cilostazol appears to prevent in-stent restenosis of high-risk patients.

Pharmacology in peripheral arterial disease: what the interventional radiologist needs to know

Peripheral arterial disease (PAD) is a progressive disease with significant morbidity and mortality. Risk factor control, using diet and lifestyle modification, exercise, and pharmacological methods, improves symptoms and reduces associated cardiovascular events in these patients. Antiplatelet agents and anticoagulants may be used to reduce the incidence of acute events related to thrombosis. The armamentarium available for symptom relief and disease modification is discussed. Novel treatments such as therapeutic angiogenesis are in their evolutionary phase with promising preclinical data.