Calcium Dobesilate for Chronic Venous Insufficiency: A Systematic Review

Pharmacokinetics, Bioequivalence, and Safety Evaluation of Two Oral Formulations of Calcium Dobesilate Capsules in Healthy Chinese Volunteers Under Fasting and Fed Conditions

To determine the pharmacokinetics (PK), safety, and bioequivalence profiles of 0.5-g calcium dobesilate capsules in both fasting and fed states for the test drug and reference drug. A randomized-sequence, single-dose, open-label, 2-period crossover study was conducted in fasted and fed healthy Chinese volunteers (Chinese Clinical Trials Registry identifier: CTR202000268-01). The fasting and fed studies, both involving 24 subjects, were conducted. A single dosage of either the reference or the test preparation was given to each eligible subject in a 1:1 ratio, followed by a 7-day rest interval before the administration of the alternative formulation. After taking the capsules, plasma samples were taken for 48 hours, and using liquid chromatography-tandem mass spectrometry, the calcium dobesilate level was determined. The PK parameters evaluated in the study included the maximum serum concentration (Cmax), area under the plasma concentration-time curve (AUC) from time 0 to the last quantifiable concentration, AUC from time 0 to infinity, half-life, time to Cmax, and terminal elimination rate constant. In addition, the safety evaluation encompassed monitoring fluctuations in vitals (temperature, pulse, and blood pressure) and laboratory tests (urinalysis, hepatic function, blood biochemistry, and hematology), as well as recording the emergence of adverse events (AEs). The geometric mean ratio (GMR) of the test/reference medications was used to assess bioequivalence by determining if the 90% confidence intervals of the GMR fell within the predefined range of 80%-125%. AEs were assessed as safety end points. The study included 48 healthy Chinese volunteers (with n = 24 each for the fasting and the fed conditions), and no subjects dropped out for any reason. The differences in the PK metrics for the test and reference drugs for both conditions were insignificant (P > .05). For bioequivalence, irrespective of whether the food was consumed or not, the range of the 90% confidence intervals of the GMR for Cmax, AUC from time 0 to the last quantifiable concentration, and AUC from time 0 to infinity was between 80% and 125%. In the experiment, no serious AEs were recorded. Our findings revealed that the calcium dobesilate capsules used as the reference and the test drugs were both bioequivalent. Irrespective of whether the healthy Chinese volunteers consumed food or not, the PK and safety profiles were comparable.

Assessment of the Tolerance of Dobenox Forte® in Patients with Chronic Venous Disease

This prospective, observational, multicenter study assessed the tolerance of Dobenox Forte®, the first approved over-the-counter product containing calcium dobesilate, in 1795 outpatients with chronic venous disease (CVD) in daily clinical practice. In addition, the effectiveness (decrease in circumferences of a more affected limb at the ankle and middle part of the calf, and changes in the severity of CVD signs) was assessed. No adverse events related to use of the preparation were reported in a period of 64 ± 20 days. Dobenox Forte® use was associated with a reduction in calf circumference by 13.1 mm (95%CI: 12.2-14.1) and in ankle circumference by 9.7 mm (95%CI: 9.2-11.0) in patients reporting swelling of the lower legs (60.0% of the cohort). A reduction in calf and ankle circumference by at least 1 cm was achieved in 34.9% and 24.9% of patients, respectively. The percentages of patients reporting moderate to very severe lower limb heaviness decreased from 96.6% to 56.0%, calf cramps decreased from 91.0% to 41.0%, calf pain decreased from 89.2% to 43.7%, swelling decreased from 86.1% to 38.8%, and burning sensation that worsens when standing decreased from 79.0% to 33.7%. The medicinal product Dobenox Forte® is well tolerated by patients and seems to effectively reduce the symptoms of CVD.

The 2023 Society for Vascular Surgery, American Venous Forum, and American Vein and Lymphatic Society clinical practice guidelines for the management of varicose veins of the lower extremities. Part II: Endorsed by the Society of Interventional Radiology and the Society for Vascular Medicine

The Society for Vascular Surgery, the American Venous Forum, and the American Vein and Lymphatic Society recently published Part I of the 2022 clinical practice guidelines on varicose veins. Recommendations were based on the latest scientific evidence researched following an independent systematic review and meta-analysis of five critical issues affecting the management of patients with lower extremity varicose veins, using the patients, interventions, comparators, and outcome system to answer critical questions. Part I discussed the role of duplex ultrasound scanning in the evaluation of varicose veins and treatment of superficial truncal reflux. Part II focuses on evidence supporting the prevention and management of varicose vein patients with compression, on treatment with drugs and nutritional supplements, on evaluation and treatment of varicose tributaries, on superficial venous aneurysms, and on the management of complications of varicose veins and their treatment. All guidelines were based on systematic reviews, and they were graded according to the level of evidence and the strength of recommendations, using the GRADE method. All ungraded Consensus Statements were supported by an extensive literature review and the unanimous agreement of an expert, multidisciplinary panel. Ungraded Good Practice Statements are recommendations that are supported only by indirect evidence. The topic, however, is usually noncontroversial and agreed upon by most stakeholders. The Implementation Remarks contain technical information that supports the implementation of specific recommendations. This comprehensive document includes a list of all recommendations (Parts I-II), ungraded consensus statements, implementation remarks, and best practice statements to aid practitioners with appropriate, up-to-date management of patients with lower extremity varicose veins.

A nationwide study of compliance of venoactive drugs in chronic venous disease patients

Purpose

Venoactive drugs are widely used to improve the symptoms and signs of chronic venous disease. This study aimed to analyze the rate of adverse events after venoactive drug prescription and subsequent compliance and switching rates.

Methods

Using the National Health Insurance Service database, individuals with at least one chronic venous disease code between January 2009 and December 2019 were identified, and 30% (2,216,780 individuals) of these were sampled. Finally, 1,551,212 patients were included, and we analyzed adverse events, compliance, and switching rates with 8 venoactive drugs, including Vitis vinifera extract, naftazone, micronized purified flavonoid fraction, Vitis vinifera leaf extract, diosmin, diobsilate calcium, bilberry fruit dried extract, and sulodexide.

Results

The most commonly prescribed venoactive drug was Vitis vinifera extract (72.2%), followed by sulodexide (9.3%), and Vitis vinifera leaf dry extract (8.2%). Adverse event rates were significantly lower in the naftazone and diosmin groups (P = 0.001 and P = 0.002, respectively) and significantly higher in the Vitis vinifera leaf dry extract group (P = 0.009). Drug adherence to sulodexide was the highest throughout the study period, followed by billberry extract and dobesilate (all P < 0.001). For most drugs, the drug switching rate was low (<5.0%).

Conclusion

Vitis vinifera extract was the most commonly prescribed venoactive drug in Korea, and drug adherence to sulodexide was the highest among all venoactive drugs. The adverse event rates were significantly lower in the naftazone and diosmin groups.

Calcium dobesilate reduces SARS-CoV-2 entry into endothelial cells by inhibiting virus binding to heparan sulfate

Recent reports demonstrate that SARS-CoV-2 utilizes cell surface heparan sulfate as an attachment factor to facilitate the initial interaction with host cells. Heparan sulfate interacts with the receptor binding domain of SARS-CoV-2 spike glycoprotein, and blocking this interaction can decrease cell infection. We and others reported recently that the family of compounds of 2,5-dihydroxyphenylic acid interferes with the binding of the positively charged groove in growth factor molecules to negatively charged cell surface heparan sulfate. We hypothesized that Calcium Dobesilate (CaD)-calcium salt of 2,5-dihydroxyphenylic acid-may also interfere with the binding of SARS-CoV-2 spike protein to heparan sulfate. Using lentiviral SARS-CoV-2 spike protein pseudotyped particles we show that CaD could significantly reduce pseudovirus uptake into endothelial cells. On the contrary, CaD did not affect cell infection with VSVG-expressing lentivirus. CaD could also prevent retention of SARS-CoV-2 spike protein in ex vivo perfused mouse kidney. Using microfluidic culture of endothelial cells under flow, we show that CaD prevents spike protein interaction with heparan sulfate glycocalyx. Since CaD has no adverse side effects and is approved in humans for other medical indications, our findings can rapidly translate into clinical studies.

Calcium dobesilate efficiency in the treatment of diabetic kidney disease through suppressing MAPK and chemokine signaling pathways based on clinical evaluation and network pharmacology

Aims: To evaluate the effectiveness and potential mechanism of calcium dobesilate (CaD) in diabetic kidney disease (DKD) patients.

Methods: We searched for available randomized controlled studies on DKD patients’ treatment with CaD through open databases. Continuous variables were expressed as standardized mean difference (SMD) with a 95% confidence interval (CI). The putative targets and possible pathways of CaD on DKD were analyzed by network pharmacology. Molecular docking was employed to verify the match between CaD and the target genes.

Results: In the meta-analysis, 42 trials were included, involving 3,671 DKD patients, of which 1,839 received CaD treatment in addition to conventional treatment, while 1,832 received conventional treatment. Compared with routine therapy, the levels of serum creatinine (Scr) and blood urea nitrogen (BUN) significantly decreased in the CaD treatment (early stage of DKD, Scr: p < 0.00001; BUN: p < 0.0001; clinical stage of DKD, Scr: p < 0.00001; BUN: p < 0.00001; kidney failure stage, Scr: p = 0.001; BUN: p = 0.004). The levels of serum cystatin C (Cys-C), urine levels of molecules reflecting kidney function (urinary albumin excretion rate (UAER) and micro glycoprotein), and inflammatory factors [hypersensitive c-reactive protein (hs-CRP)] were reduced compared with control groups, while glomerular filtration rate (GFR) was increased in patients treated with CaD for 12 weeks. CaD also showed a better effect on improving endothelial function. Network pharmacology results showed that the interaction pathway between CaD and DKD was mainly enriched in MAPK and chemokine signaling pathways. AKT1, CASP3, IGF1, MAPK8, and CCL5 might be the key targets for CaD in treating DKD.

Conclusion: Combination with CaD is effective and safe in patients with DKD. Inhibition of MAPK and chemokine signaling pathways might be vital in treating CaD in DKD patients.

Management of Lower Extremity Pain from Chronic Venous Insufficiency: A Comprehensive Review

PURPOSE OF REVIEW

Chronic venous insufficiency is found to some extent in a large proportion of the world's population, especially in the elderly and obese. Despite its prevalence, little research has been pursued into this pathology when compared to similarly common conditions. Pain is often the presenting symptom of chronic venous insufficiency and has significant deleterious effects on quality of life. This manuscript will describe the development of pain in chronic venous insufficiency, and will also review both traditional methods of pain management and novel advances in both medical and surgical therapy for this disease.

RECENT FINDINGS

Pain in chronic venous insufficiency is a common complication which remains poorly correlated in recent studies with the clinically observable extent of disease. Although lifestyle modification remains the foundation of treatment for pain associated with chronic venous sufficiency, compression devices and various pharmacologic agents have emerged as safe and effective treatments for pain in these patients. In patients for whom these measures are insufficient, recently developed minimally invasive vascular surgical techniques have been shown to reduce postsurgical complications and recovery time, although additional research is necessary to characterize long-term outcomes of these procedures. This review discusses the latest findings concerning the pathophysiology of pain in chronic venous insufficiency, conservative and medical management, and surgical strategies for pain relief, including minimally invasive treatment strategies.

Phlebotonics for venous insufficiency

BACKGROUND

Chronic venous insufficiency (CVI) is a condition in which veins are unable to transport blood unidirectionally towards the heart. CVI usually occurs in the lower limbs. It might result in considerable discomfort, with symptoms such as pain, itchiness and tiredness in the legs. Patients with CVI may also experience swelling and ulcers. Phlebotonics are a class of drugs often used to treat CVI. This is the second update of a review first published in 2005.

OBJECTIVES

To assess the efficacy and safety of phlebotonics administered orally or topically for treatment of signs and symptoms of lower extremity CVI.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and Clinicaltrials.gov trials register up to 12 November 2019. We searched the reference lists of the articles retrieved by electronic searches for additional citations. We also contacted authors of unpublished studies.

SELECTION CRITERIA

We included randomised, double-blind, placebo-controlled trials (RCTs) assessing the efficacy of phlebotonics (rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, Centella asiatica, disodium flavodate, French maritime pine bark extract, grape seed extract and aminaftone) in patients with CVI at any stage of the disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the quality of included RCTs. We estimated the effects of treatment by using risk ratios (RRs), mean differences (MDs) and standardized mean differences (SMDs), according to the outcome assessed. We calculated 95% confidence intervals (CIs) and percentage of heterogeneity (I²). Outcomes of interest were oedema, quality of life (QoL), assessment of CVI and adverse events. We used GRADE criteria to assess the certainty of the evidence.

MAIN RESULTS

We identified three new studies for this update. In total, 69 RCTs of oral phlebotonics were included, but only 56 studies (7690 participants, mean age 50 years) provided quantifiable data for the efficacy analysis. These studies used different phlebotonics (28 on rutosides, 11 on hidrosmine and diosmine, 10 on calcium dobesilate, two on Centella asiatica, two on aminaftone, two on French maritime pine bark extract and one on grape seed extract). No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria. Moderate-certainty evidence suggests that phlebotonics probably reduce oedema slightly in the lower legs, compared with placebo (RR 0.70, 95% CI 0.63 to 0.78; 13 studies; 1245 participants); and probably reduce ankle circumference (MD -4.27 mm, 95% CI -5.61 to -2.93 mm; 15 studies; 2010 participants). Moderate-certainty evidence shows that phlebotonics probably make little or no difference in QoL compared with placebo (SMD -0.06, 95% CI -0.22 to 0.10; five studies; 1639 participants); and similarly, may have little or no effect on ulcer healing (RR 0.94, 95% CI 0.79 to 1.13; six studies; 461 participants; low-certainty evidence). Thirty-seven studies reported on adverse events. Pooled data suggest that phlebotonics probably increase adverse events slightly, compared to placebo (RR 1.14, 95% CI 1.02 to 1.27; 37 studies; 5789 participants; moderate-certainty evidence). Gastrointestinal disorders were the most frequently reported adverse events. We downgraded our certainty in the evidence from 'high' to 'moderate' because of risk of bias concerns, and further to 'low' because of imprecision.

AUTHORS' CONCLUSIONS

There is moderate-certainty evidence that phlebotonics probably reduce oedema slightly, compared to placebo; moderate-certainty evidence of little or no difference in QoL; and low-certainty evidence that these drugs do not influence ulcer healing. Moderate-certainty evidence suggests that phlebotonics are probably associated with a higher risk of adverse events than placebo. Studies included in this systematic review provided only short-term safety data; therefore, the medium- and long-term safety of phlebotonics could not be estimated. Findings for specific groups of phlebotonics are limited due to small study numbers and heterogeneous results. Additional high-quality RCTs focusing on clinically important outcomes are needed to improve the evidence base.

Calcium Dobesilate and Micro-vascular diseases

Micro-vascular diseases and its associated complications continue to be a significant health problem worldwide. Vascular lesions from microvascular involvement lead to impaired blood flow and contribute to damage and dysfunction of one or more target organs, that is, the heart, kidneys, eyes, and nervous system. Calcium Dobesilate Drug (CAD) is an established vasoactive and angioprotective drug that has shown a unique, multitarget mode of action in several experimental studies and in different animal models of diabetic microvascular complications. CAD has been widely used as an antioxidant and a vascular protective agent. At present, the application of Calcium Dobesilate is mainly related to Micro-vascular damage-related diseases, such as diabetic retinopathy (DR) and diabetic nephropathy (DN), and it is found to significantly improve the related symptoms. Its beneficial effects make it an attractive therapeutic compound especially in the early stages of these diseases. Scholars at home and abroad have studied the effectiveness, safety, and mechanisms of the related diseases, furthermore, the subjects involved patients and animal models, they have found some new clinical effects of this medicine. This paper makes a brief summary of a research progress of clinical application about Vascular injury related diseases and other aspects.

[Pharmacology of the drugs prescribed for chronic venous diseases]

The main groups of the drugs used for pharmacotherapy of chronic venous disease are considered. The main therapeutic targets of the drugs including their effect on venous wall tone, permeability and inflammation are described.

Selected Physicochemical Properties of Lyophilized Hydrogel with Liposomal Fraction of Calcium Dobesilate

Lyophilization is the process of drying and improving the stability of various pharmaceutical preparations. In this work we evaluated the properties of 11 hydrophilic gels calcium dobesilate with liposomes based on soybean lecithin, subjected to the freeze-drying procedure. Liposomes were produced by using method thin lipid film. Lyophilization was carried out under conditions of temperature equal (-30 °C) and pressure 0.37 mbar. We evaluated the preparations with dynamic light scattering (DLS) method, optical microscopy and Fourier-transform infrared spectroscopy (FTIR). In this work we presented the average results for the particle diameter in the sample and PDI (polydispersity index) value for the samples that produced the results. When testing using the DLS method on a Malvern Zetaseizer, results for 7 samples were not obtained. Two of next four samples were characterized by an increased size of the liposome particle resulting from a lower concentration of ethanol compared to the rest of them. Three samples under the microscope did not show any differences. It was possible only to see single crystals probably of undissolved calcium dobesilate. Some clusters were observed in the 4 samples, and when they appeared they were very small. The aggregates and irregular liposomes present in the rest of the samples may have been formed due to the destabilizing activity of ethanol towards lipid membranes. In the FTIR spectrum for MC, the peak was observed at the wavenumber of ca. 2900 cm-1 and of about 1050 cm-1. In case of pure calcium dobesilate we observed low pick at the wavenumber of about 3400 cm-1. The spectrum has a low peak at the wavenumber of 1450 cm-1 and intense peaks ranging from approx. 1000 cm-1 to approx. 1200 cm-1. Decay of the lecithin peak in formulations with liposomes at 1725 cm-1 wavelength may indicate the occurrence of the hydrolysis reaction in the system. Probably there was a hydrolysis of the ester bond connecting the rest of the phosphoric acid and the choline with the glycerol residue.

Efficacy of subcutaneous lidocaine injection in venous insufficiency: a prospective, randomized, controlled study, and new treatment protocol

[Purpose] The purpose of this study was to evaluate the efficacy of subcutaneous injection with lidocaine in patients with chronic venous insufficiency in the early stage. [Subjects and Methods] Patients (n=50) randomized to the treatment group received subcutaneous injections from a mixture of physiological saline sterile solution and lidocaine once a week to both legs below the knee for 5 sessions. Patients in the treatment group were also given ankle pumping exercises and compression stockings throughout the treatment. Patients randomized to the control group (n=50) received only ankle pumping exercises and compression stockings. Patients were evaluated using the visual analog scale (VAS) for pain and Chronic Venous Disease Quality of life Questionnaire (CIVIQ-20) for quality-of-life at months 1, 3, 6, at the end of month 12, and at the end of the injection treatment for 5 sessions. [Results] CIVIQ-20 and VAS results were significantly lower in the treatment group, than in the control group at months 1, 3 and 6. However, CIVIQ-20 and VAS results were not significantly different, compared with the pre-operative period at month 12. [Conclusion] We observed that 5-week subcutaneous lidocaine injection treatment was effective in patients who do not respond to oral medical treatment or in whom surgery is not considered.

A Review of the Microcirculation in Skin in Patients With Chronic Venous Insufficiency: The Problem and the Evidence Available for Therapeutic Options

Impairment of the cutaneous microcirculation is a major predisposing factor in inflammation and ulceration in patients with chronic venous insufficiency (CVI). Increase of capillary filtration rate predisposes to the formation of edema. Local lymphedema is a complication of CVI, often underdiagnosed. This review is focused on CVI but excludes the complication of ulceration. Treatment of microcirculatory dysfunction can be done by pharmacologic intervention or compression therapy or using a combination of both. This review is focused on drugs that have been evaluated by randomized prospective controlled trials. The following compounds are discussed: horse chestnut seed extracts, flavonoids, red vine leaves extracts, total triterpenic fraction of Centella asiatica (L), prociadins, calcium dobesilate, and pentoxifylline. The microcirculatory effects of compression therapy using bandages or stockings are also reviewed. The major microcirculatory effects that have been shown are the reduction of capillary filtration rate and improvements in levels of transcutaneous partial pressures of oxygen and carbon dioxide (TcPO2 and TcPCO2). Available data suggest that a combination of pharmacologic and compression therapy may have some additive effects.

Phlebotonics for venous insufficiency

BACKGROUND

Chronic venous insufficiency (CVI) is a common condition caused by valvular dysfunction with or without associated obstruction, usually in the lower limbs. It might result in considerable discomfort with symptoms such as pain, itchiness and tiredness in the legs. Patients with CVI may also experience swelling and ulcers. Phlebotonics are a class of drugs often used to treat CVI. This is an update of a review first published in 2005.

OBJECTIVES

To assess the efficacy and safety of phlebotonics administered both orally and topically for treatment of signs and symptoms of lower extremity CVI.

SEARCH METHODS

For this update, the Cochrane Vascular Trials Search Co-ordinator (TSC) searched the Specialised Register (August 2015), as well as the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 7). The reference lists of the articles retrieved by electronic searches were searched for additional citations. We also contacted pharmaceutical companies and searched the World Health Organization (WHO) International Clinical Trials Registry Platform Search Portal for ongoing studies (last searched in August 2015).

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled trials (RCTs) assessing the efficacy of rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, Centella asiatica, disodium flavodate, french maritime pine bark extract, grape seed extract and aminaftone in patients with CVI at any stage of the disease.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the quality of included RCTs. We estimated the effects of treatment by using risk ratios (RRs), mean differences (MDs) and standardised mean differences (SMDs), according to the outcome assessed. We calculated 95% confidence interval (CIs) and percentage of heterogeneity (I(2)). Additionally, we performed sensitivity analyses.

MAIN RESULTS

We included 66 RCTs of oral phlebotonics, but only 53 trials provided quantifiable data (involving 6013 participants; mean age 50 years) for the efficacy analysis: 28 for rutosides, 10 hidrosmine and diosmine, nine calcium dobesilate, two Centella asiatica, two aminaftone, two french maritime pine bark extract and one grape seed extract. No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria.Moderate-quality evidence suggests that phlebotonics reduced oedema in the lower legs compared with placebo. Phlebotonics showed beneficial effects among participants including reduced oedema (RR 0.70, 95% CI 0.63 to 0.78; I(2) = 20%; 1245 participants) and ankle circumference (MD -4.27 mm, 95% CI -5.61 to -2.93 mm; I(2) = 47%; 2010 participants). Low-quality evidence reveals no difference in the proportion of ulcers cured with phlebotonics compared with placebo (RR 0.94, 95% CI 0.79 to 1.13; I(2) = 5%; 461 participants). In addition, phlebotonics showed greater efficacy for trophic disorders, cramps, restless legs, swelling and paraesthesia, when compared with placebo. We identified heterogeneity for the variables of pain, itching, heaviness, quality of life and global assessment by participants. For quality of life, it was not possible to pool the studies because heterogeneity was high. However, high-quality evidence suggests no differences in quality of life for calcium dobesilate compared with placebo (MD -0.60, 95% CI -2.15 to 0.95; I(2) = 40%; 617 participants), and low-quality evidence indicates that in the aminaftone group, quality of life was improved over that reported in the placebo group (MD -10.00, 95% CI -17.01 to - 2.99; 79 participants). Moderate-quality evidence shows that the phlebotonics group had greater risk of non-severe adverse events than the placebo group (RR 1.21, 95% CI 1.05 to 1.41; I(2) = 0; 3975 participants). Gastrointestinal disorders were the most frequently reported adverse events.

AUTHORS' CONCLUSIONS

Moderate-quality evidence shows that phlebotonics may have beneficial effects on oedema and on some signs and symptoms related to CVI such as trophic disorders, cramps, restless legs, swelling and paraesthesia when compared with placebo but can produce more adverse effects. Phlebotonics showed no differences compared with placebo in ulcer healing. Additional high-quality RCTs focused on clinically important outcomes are needed to improve the evidence base.

A randomized, double-blind, placebo-controlled, clinical study on the efficacy and safety of calcium dobesilate in the treatment of chronic venous insufficiency

OBJECTIVE

To show the superiority of 500 mg calcium dobesilate vs. placebo in reduction of edema of the lower limbs in patients with chronic venous insufficiency, Clinical, Etiological, Anatomical and Pathophysiological classes C3/C4.

METHODS

A total of 351 patients were randomized (n = 174 calcium dobesilate, n = 177 placebo). Active treatment was 500 mg calcium dobesilate, three times daily for 12 weeks, with a 12-week follow-up.

RESULTS

At the end of treatment, the relative volume change in the most pathological leg was -0.6 ± 4.8% with calcium dobesilate compared to -0.3 ± 3.3% with placebo (p = 0.09). At the end of follow-up, this was -1.01 ± 5.4% for calcium dobesilate vs. -0.08 ± 3.5% for placebo (p = 0.002).

CONCLUSIONS

Calcium dobesilate treatment resulted in no significant volume change in the most pathological leg between baseline and end of treatment. However, the calcium dobesilate group showed a significantly greater volume decrease in the most pathological leg at the end of follow-up. Calcium dobesilate was well-tolerated, with a safety profile consistent with previously published data.

Pharmacological treatment of hemorrhoids: a narrative review

INTRODUCTION

Hemorrhoid disease is the cause of most proctologic complaints and hundreds of medical and surgical therapies have been proposed to relieve symptoms. However, the role and the correct indication of medical treatments are still controversial. Further, the utility of conservative measures are rarely scientifically supported by adequate trials.

AREAS COVERED

This narrative review is based on the search and analysis of full papers in English language selected from PubMed in the past 30 years using the following MeSH Editing: hemorrhoids, conservative treatment, medical treatment and hemorrhoids, pregnancy and hemorrhoids, thrombosed hemorrhoids, randomized trials and hemorrhoids, postoperative pain and hemorrhoids.

EXPERT OPINION

Early stages (I/II degrees) of this disease could be effectively managed conservatively with several approaches as lifestyle changes, fiber supplement, topical ointments and phlebotonic drugs. The more advanced hemorrhoid stages (III/IV degrees) need some type of surgery, but medical therapy is still useful to minimize anal symptoms as a bridge-to-surgery treatment. Further, post-hemorrhoidectomy pain, hemorrhoidal crisis even in pregnancy could benefit from the adjunct of local and systemic medical treatment. This expert opinion, based also on long-lasting clinical practice, also supports the use of medical treatment in symptoms relief in patients with hemorrhoid disease.

Post-thrombotic syndrome: a clinical review

Up to half of patients with proximal deep vein thrombosis (DVT) will develop post-thrombotic syndrome (PTS) despite optimal anticoagulant therapy. PTS significantly impacts upon quality of life and has major health-economic implications. This narrative review describes the pathophysiology, risk factors, and diagnosis, prevention and treatment of PTS, to improve our understanding of the disease and guide treatment. Relevant articles were identified through systematic searches of the PubMed, EMBASE and Cochrane databases between 1966 and November 2011. Studies were included for detailed assessment if they met the following criteria: published in English, human study participants, study population aged > 18 years, and lower limb post-thrombotic syndrome. All non-systematic reviews and single patient case reports were excluded. Recurrent thrombosis, thrombus location and obesity are major risk factors, whereas the importance of gender and age remain uncertain. The diagnosis of PTS is based on clinical findings in patients with a known history of DVT. Several clinical scales have been described, with the Villalta Score gaining increasing popularity. Adequate anticoagulation and use of elastic compression stockings (ECS) following DVT can reduce the incidence of PTS. Catheter-directed thrombolysis and mechanical thrombectomy of acute DVT may preserve valvular function. Studies to date of these techniques are encouraging, and have reported improved hemodynamics and a reduced incidence of PTS. The management of established PTS is challenging. Compression therapy, aimed at reducing the underling venous hypertension, remains the mainstay of treatment. This is despite a paucity of high-quality evidence to support its use. Pharmacologic and surgical treatments have also been described, with a number of studies citing symptomatic improvement.

A Systematic Review of the Efficacy of Centella asiatica for Improvement of the Signs and Symptoms of Chronic Venous Insufficiency

We aimed to assess the efficacy of Centella asiatica for improvement of the signs and symptoms of chronic venous insufficiency (CVI). We searched 13 electronic databases including the Cochrane Central Register of Controlled Trials for randomised controlled trials assessing the efficacy of Centella asiatica for CVI. Two review authors independently selected studies, assessed the risks of bias of included studies and extracted data. The treatment effects of similar studies were pooled whenever appropriate. Eight studies met the inclusion criteria. The pooling of data of similar studies showed that Centella asiatica significantly improved microcirculatory parameters such as transcutaneous partial pressure of CO2 and O2, rate of ankle swelling and venoarteriolar response. Three out of the eight studies did not provide quantitative data. However, these studies reported that patients treated with Centella asiatica showed significant improvement in CVI signs such as leg heaviness, pain and oedema. Our results show that Centella asiatica may be beneficial for improving signs and symptoms of CVI but this conclusion needs to be interpreted with caution as most of the studies were characterised by inadequate reporting and thus had unclear risks of bias, which may threaten the validity of the conclusions.

In vitro effect of calcium dobesilate on oxidative/inflammatory stress in human varicose veins

AIM

To determine whether calcium dobesilate can act in chronic venous insufficiency by similar antioxidant, anti-inflammatory mechanisms as in diabetic retinopathy.

METHODS

Calcium dobesilate was tested in vitro for its protective action against oxidative/inflammatory stress in human varicose veins. Varicose greater saphenous veins were obtained from 14 patients (11 men, 3 women) aged 53-65 years. Oxidative stress was induced exogenously in the vein segments, with the phenazine methosulphate (PMS)/NADH couple. Total antioxidant status (TAS) and malondialdehyde (MDA) contents were used as markers of oxidative stress.

RESULTS

Calcium dobesilate significantly prevented oxidative disturbances in the micromolar range. PMS/NADH-dependent TAS decrease was fully prevented with IC(50) = 11.4 ± 2.3 µmol/L (n = 6 veins), whereas MDA increase was fully prevented with IC(50) = (102 ± -3) µmol/L (n = 6 veins). Calcium dobesilate acted quali- and quantitatively like rutin, the reference compound. Comparison with pharmacokinetic data suggests that calcium dobesilate can act at therapeutic concentrations.

CONCLUSION

Calcium dobesilate protected human varicose veins against oxidative stress in vitro at levels that correspond to therapeutic concentrations. Further studies are required to investigate whether a similar action is found in varicose veins from patients orally treated with calcium dobesilate.

Pharmacological treatment in patients with C4, C5 and C6 venous disease

Background

A range of surgical, endovenous, physical and medical treatments are available for patients with chronic venous disease. The aim of this review was to evaluate the evidence for pharmacological agents used for the treatment of chronic venous disease.

Methods

A literature search was performed using Pubmed, Embase, Cochrane and Google Scholar databases. The initial search terms ‘varicose vein’, ‘venous ulcer’, ‘venous disease’ and ‘lipodermatosclerosis’ were used to identify relevant clinical studies of pharmacotherapy in patients with chronic venous disease (C4–C6).

Results

A huge range of naturally occurring and synthetic drugs have been studied in patients with chronic venous disease. For patients with C4 venous disease, micronized purified flavonoid fraction (MPFF), oxerutin, rutosides and calcium dobesilate may reduce venous symptoms and oedema. MPFF and pentoxifylline have been shown to improve venous ulcer healing when used in addition to multilayer compression bandaging. The clinical benefits of other medications remain unproven. Reliability of meta-analyses was limited by study heterogeneity, small sample sizes and lack of long-term follow-up.

Conclusions

In prospective randomized studies, MPFF (Daflon®), other flavonoid derivatives and pentoxifylline have demonstrated clinical benefits in patients with C4–C6 venous disease. Pharmacotherapy should be part of a range of treatment options in the modern management of patients with chronic venous disorders.

Phlebotonics for venous insufficiency

BACKGROUND

Chronic venous insufficiency (CVI) is a common condition caused by inadequate blood flow through the veins, usually in the lower limbs. It can result in considerable discomfort with symptoms such as pain, itchiness and tiredness in the legs. Sufferers may also experience swelling and ulcers. Phlebotonics are a class of drugs that are often used to treat CVI.

OBJECTIVES

To assess the efficacy of oral or topical phlebotonics.

SEARCH STRATEGY

We searched the Cochrane Peripheral Vascular Diseases Group trials register (April 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2005), MEDLINE (January 1966 to April 2005), EMBASE (January 1980 to April 2005) and reference lists of articles. We also contacted pharmaceutical companies.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials (RCTs) assessing the efficacy of rutosides, hidrosmine, diosmine, calcium dobesilate, chromocarbe, centella asiatica, disodium flavodate, french maritime pine bark extract, grape seed extract and aminaftone in CVI patients at any stage of the disease.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data and assessed trial quality. The effects of treatment were estimated by relative risk (RR) or by standardised mean differences (SMD) by applying a random effects statistical model. Sensitivity analyses were also performed.

MAIN RESULTS

Fifty-nine RCTs of oral phlebotonics were included, but only 44 trials involving 4413 participants contained quantifiable data for the efficacy analysis: 23 of rutosides, ten of hidrosmine and diosmine, six of calcium dobesilate, two of centella asiatica, one of french maritime pine bark extract, one of aminaftone and one of grape seed extract. No studies evaluating topical phlebotonics, chromocarbe, naftazone or disodium flavodate fulfilled the inclusion criteria. Outcomes included oedema, venous ulcers, trophic disorders, subjective symptoms (pain, cramps, restless legs, itching, heaviness, swelling and paraesthesias), global assessment measures and side effects. The results of many variables were heterogeneous. Phlebotonics showed some global benefit (i.e. oedema reduction) (relative risk 0.72, 95% confidence interval 0.65 to 0.81). The benefit for the remaining CVI signs and symptoms must be evaluated by phlebotonic group. There were no quantifiable data on quality of life.

AUTHORS' CONCLUSIONS

There is not enough evidence to globally support the efficacy of phlebotonics for chronic venous insufficiency. There is a suggestion of some efficacy of phlebotonics on oedema but this is of uncertain clinical relevance. Due to the limitations of current evidence, there is a need for further randomised, controlled clinical trials with greater attention paid to methodological quality.

Calcium Dobesilate in the Treatment of Diabetic Retinopathy

The incidence of diabetic retinopathy is still increasing in developed countries. Tight glycemic control and laser therapy reduce vision loss and blindness, but do not reverse existing ocular damage and only slow the progression of the disease. New pharmacologic agents that are currently under development and are specifically directed against clearly defined biochemical targets (i.e. aldose reductase inhibitors and protein kinase C-beta inhibitors) have failed to demonstrate significant efficacy in the treatment of diabetic retinopathy in clinical trials. In contrast, calcium dobesilate (2,5-dihydroxybenzenesulfonate), which was discovered more than 40 years ago and is registered for the treatment of diabetic retinopathy in more than 20 countries remains, to our knowledge, the only angioprotective agent that reduces the progression of this disease. An overall review of published studies involving calcium dobesilate (CLS 2210) depicts a rather 'non-specific' compound acting moderately, but significantly, on the various and complex disorders that contribute to diabetic retinopathy. Recent studies have shown that calcium dobesilate is a potent antioxidant, particularly against the highly damaging hydroxyl radical. In addition, it improves diabetic endothelial dysfunction, reduces apoptosis, and slows vascular cell proliferation.