Incidence and causes of heparin-induced skin lesions

Fatal Course of Cutaneous Cholesterol Embolization Syndrome: A Case Report

Cholesterol embolization syndrome is an increasing but underestimated problem after endovascular intervention or after the start of thrombolytic therapies. Embolies from the aortic wall involves abdominal organs and the skin of the lower extremities or buttocks. In our case a progressive ulceration and necroses occurs spontaneously. Endovascular treatment of the lower extremities was successful for a short period. Due to the progression of necrosis, both legs were amputated. Biopsies were taken from the skin were initially no directions to the diagnosis of Cholesterol embolization syndrome. After a second elliptical excision biopsy the diagnosis of cholesterol embolization syndrome was confirmed. Because the rapid progression of skin necroses despite the treatment of prednisone, patient died due to sepsis and renal failure. This case shows when arterial revascularization is performed and progression in skin necrosis occurs despite optimal arterial vascular status the diagnosis CES should be considered and treated in an early state of disease.

Delayed-Type Heparin Allergy: Intravenous Tolerance Despite Inflammatory Skin Reaction After Subcutaneous Injection

BACKGROUND

Heparin allergy most frequently manifests as delayed-type hypersensitivity (DTH) causing an itchy inflammatory skin reaction at the site of subcutaneous injection. An important differential diagnosis is circumscribed skin necrosis due to heparin-induced thrombocytopenia.

OBJECTIVES

An inflammatory skin reaction to subcutaneously injected heparin generally entails the quest for alternative anticoagulation; concerns may particularly arise in an emergency situation requiring intravenous heparin administration.

METHODS

All heparin DTH cases seen in our department over the last 17 years underwent standardized allergy diagnostics including challenge testing, that is, subcutaneous injection of fondaparinux and intravenous administration of unfractionated heparin (UFH).

RESULTS

Of a total of 50 patients with confirmed heparin allergy, DTH was found in 48 (96.0%), and immediate-type, presumably IgE-mediated hypersensitivity was diagnosed in only 2 (4.0%). In the 48 DTH cases, intradermal testing revealed broad cross-reactivity between UFH and low-molecular-weight heparins (LMWH) including nadroparin, dalteparin, and enoxaparin. Cross-reactivity with (or concomitant sensitization to) fondaparinux was seen in only 3 (6.3%) cases. Intravenous administration of UFH was tolerated by all 45 patients challenged, despite DTH to UFH and LMWH as demonstrated by intradermal testing.

CONCLUSIONS

If an inflammatory skin reaction at the site of subcutaneously injected heparin is observed or reported without any evidence of skin necrosis or thrombocytopenia, intravenous administration of UFH seems to be sufficiently safe and may be considered without allergy testing if urgently indicated in an emergency situation. Fondaparinux is the most suitable alternative for subcutaneous application.

Localized and Generalized Skin Adverse Drug Reactions to Nadroparin Calcium Injection in 6 Cases of Pregnant Women

Background

Despite the increasing number of skin adverse drug reactions caused by nadroparin calcium have been reported, mostly, little is known regarding of their details of clinical characteristics, especially for generalized skin adverse drug reactions. We sought to evaluate localized and generalized characteristics of the skin adverse drug reaction to nadroparin calcium injection in pregnant women.

Methods

A retrospective study was conducted on 6 pregnant women, who experienced localized and generalized skin adverse drug reactions during long-term nadroparin calcium injection. The patients' clinical and imaging information were retrieved from medical records. The skin prick test, patch test, and intradermal test were performed after they stopped lactation. Causality assessment of suspected adverse drug reactions was performed on these cases.

Results

The average total dose of nadroparin calcium injection in the 6 cases was 64.17 ± 22.66. Localized skin adverse drug reaction, manifested as erythema at the injection point, appeared after 47.5 ± 17.4 days of subcutaneous injection of nadroparin calcium. Generalized urticaria-like lesions, progressing from the injection site on the abdomen, appeared in 5.17 ± 3.60 days after the first appearance of localized reaction, while laboratory test results revealed essential peripheral blood eosinophilia. All rashes in the 6 cases subsided in 2–5 weeks after drug withdrawal. After delivery, 5 of 6 cases received complete skin tests to evaluate drug hypersensitivity. Results presented positive in the intradermal test within 7 days. Both the skin prick test and skin patch test were negative. Localized skin reactions and generalized urticaria-like adverse drug reactions were considered as definitely and probably caused by nadroparin calcium injection, respectively.

Conclusion

Subcutaneous injection of nadroparin calcium in pregnant women appears to be at risk of localized and generalized urticaria-like adverse drug reaction. It is important to follow up the pregnant woman during nadroparin calcium injection for evaluating adverse drug reactions. Timely detection of symptoms is pivotal in early diagnosis and treatment of adverse drug reactions.

Improved hemocompatibility of polysulfone hemodialyzers with Endexo® surface modifying molecules

Anticoagulation therapy is widely used to reduce clotting during hemodialysis (HD), but may cause adverse effects in end-stage kidney disease patients. A new hemodialyzer with a membrane modified by surface modifying molecule was developed to improve hemocompatibility that aimed to reduce the need for anticoagulation during dialysis treatments. We compared membrane surface characteristics and in vitro hemocompatibility of the new hemodialyzer to the standard polysulfone (PSF) hemodialyzer membrane. Scanning electron microscopy, contact angle measurement (68° ± 3° test vs. 41.6° ± 6° control), and X-ray photoelectron spectrometry measurement for fluorine atomic % (7.4% ± 0.4% test vs. not detectable control), showed that the membrane surface was modified with surface modifying macromolecule (SMM1) but maintained membrane structure and surface hydrophilicity. Zeta potential of the blood-contacting surface showed that the absolute surface charge was reduced at neutral pH (-3.3 mV ± 1.1 mV test vs. -15.6 mV ± 1.0 mV control). Platelet count reduction was significantly less for the SMM1-modified dialyzer (40.88% ± 21.89%) compared to the standard PSF dialyzer (62.62% ± 34.13%), along with Platelet Factor 4 (1824.10 ng/ml ± 436.26 ng/ml test vs. 2479.00 ng/ml ± 852.96 ng/ml control). These studies demonstrate the successful incorporation of SMM1 into the new hemodialyzer with the expected results. Our in vitro experiments indicate that the SMM1-modified hemodialyzers could improve hemocompatibility compared to standard PSF hemodialyzers and have the potential to minimize the patient's anticoagulant requirements during HD. Additional research with SMM1 additives incorporated into the entire dialysis circuit and use in a clinical settings are required to confirm these promising findings.

Extensive skin necrosis after periprosthetic knee infection: a case that highlights the possibility of complications induced by low-molecular-weight heparin

We describe a case of a patient with atrial fibrillation, anticoagulated with dabigatran, that developed severe knee skin necrosis in the setting of an acute periprosthetic knee infection, after initiating low-molecular-weight heparin. A wide range of etiology hypotheses was discussed within a multidisciplinary team. The complex approach consisted of treating the underlying infection, multiple types of soft-tissue management, and stopping enoxaparin.

Cold Application on Bruising at the Subcutaneous Heparin Injection Site: A Systematic Review and Meta-Analysis

Despite the documented clinical efficacy, the injection of subcutaneous heparin can be associated with adverse drug reactions including bruising at the injection site. This study sought to systematically assess current evidence regarding the effect of cold application as a fundamental nursing intervention on the occurrence and size of bruising at the injection site in patients receiving subcutaneous heparin. A systematic review and meta-analysis of randomized controlled trials and quasi-experimental studies was performed. Web of Knowledge, PubMed (including MEDLINE), Scopus, Embase, Cochrane library, gray literature, and cross-referencing from reference lists were searched from 2000 to 2019. Quality of selected studies was assessed using the Cochrane risk of bias appraisal tool for randomized controlled trials and the JBI MASTARI appraisal tool for quasi-experimental studies. The search yielded 3,220 articles, but consideration of inclusion criteria led to final selection of 9 articles. The meta-analysis showed that cold application significantly reduced the relative occurrence of bruising at the subcutaneous heparin injection site by 40% (relative risk, 0.60; 95% confidence interval [0.39, 0.91]) and reduced the bruising size (standardized mean difference, -2.78; 95% confidence interval [-4.34, -1.22]). Cold application as a fundamental nursing intervention can be an effective intervention to prevent adverse drug reactions at the injection site in terms of the occurrence and size of bruising in patients receiving subcutaneous heparin.

Enoxaparin induced eruptive angiokeratoma, an extremely rare side effect

Enoxaparin is one of the most commonly used anticoagulants in the management of thromboembolic events. Herein we report a unique case of enoxaparin induced eruptive angiokeratomas in a patient with a history of ischemic cardiomyopathy who presented with acute decompensated heart failure and a new-onset generalized skin rash that bleeds on trauma, suggestive of angiokeratomas. Dermoscopic examination, as well as skin biopsy, were done upon clinical suspicion of eruptive angiokeratomas, to confirm the diagnosis. Dermoscopy showed dark lacunae surrounded by erythema, while skin biopsy revealed dilated congested capillaries lined by flat endothelial cells in the papillary dermis, both confirming the diagnosis of angiokeratoma. Enoxaparin induced eruptive angiokeratomas was suspected when the skin eruption showed spontaneous dramatic resolution upon withdrawal of enoxaparin followed by its substitution with warfarin, during the course of the patient's treatment. Enoxaparin induced eruptive angiokeratoma is an extremely rare side effect. Physicians should have a high index of clinical suspicion, and promptly discontinue the drug, as this is the only proven treatment for this condition.

Pruritus Associated with Commonly Prescribed Medications in a Tertiary Care Center

Background: Sparse data are available on rates of drug-induced pruritus, a well-recognized adverse reaction. We sought to assess relative rates of pruritus associated with commonly prescribed medications. Methods: Using the electronic medical record system EPIC, retrospective data were collected on patients seen at Johns Hopkins who received a medication of interest in a five-year period (2013–2018). Sequential criteria were used to identify the subpopulation who presented with a chief complaint of “pruritus” or diagnosis of “itching” within three months of receiving drugs. Results: We identified 9802 patients with pruritus after drug initiation and 1,085,404 patients without. A higher proportion of those with pruritus were female (70%) than those without (58%), p < 0.001. Patients in both groups were most commonly 50 to 79 years old. A higher proportion of patients with pruritus were black (40%) compared to those without (23%), p < 0.001. In this study, the highest rates of pruritus were observed with heparin (1.11%), trimethoprim-sulfamethoxazole (1.06%), and calcium channel blockers (0.92%). Psychiatric/neurologic drugs used to treat pruritus were associated with low rates of itch. Conclusions: Certain cardiovascular and antimicrobial agents are associated with increased frequencies of pruritus. This knowledge may guide providers in clinical selection of commonly used agents to minimize adverse effects associated with reduced compliance.

Non-immediate heparin and heparinoid cutaneous allergic reactions: a role for fondaparinux

Non-immediate allergic cutaneous reactions to heparins have been increasingly reported, typically manifesting as large, eczematous plaques at sites of subcutaneous injection. Patients may demonstrate cross-reactivity between unfractionated heparin, low molecular weight heparin and semi-synthetic heparinoids, making finding an alternative difficult. Fondaparinux has been identified as a useful alternative in such patients; here we present the first two documented cases in Australia and a literature review.

Hypersensitivity reactions to low molecular weight heparins: different patterns of cross-reactivity in 3 patients

Low molecular weight heparins (LMWHs) are used for a variety of indications. The most common type of hypersensitivity reactions to LMWHs are delayed-type hypersensitivity reactions (DHR). Immediate-type hypersensitivity reactions (IHR) occur only sporadically. Cross-reactivity of different LMWHs is a common and unpredictable problem. We present 2 cases of patients who developed DHR to nadroparin and enoxaparin, respectively. The third case presents a patient who developed IHR to nadroparin. Skin tests confirmed the hypersensitivity in all cases. In the cases of DHR, a skin test negative LMWH was identified and was tolerated in a challenge test. In the IHR case, cross-reactivity to all tested LMWHs was established. We hypothesize that the degree of cross-reactivity might depend on the type of hypersensitivity reaction with immediate reactions linked to more extensive cross-reactivity than delayed reactions. This is important to consider because, at least in some cases, a safe alternative LMWH can be identified.

Higher Adherence to Treatment With Low-Molecular-Weight-Heparin Nadroparin Than Enoxaparin Because of Side Effects in Cancer-Associated Venous Thromboembolism

Current guidelines recommend low-molecular-weight-heparins (LMWH) monotherapy for 3 to 6 months as first-line treatment for cancer-associated venous thromboembolism (VTE). In clinical practice, enoxaparin and nadroparin are common agents used. However, differences in therapy adherence between these LMWHs have never been reported. Therefore, our aim was to compare adherence to enoxaparin and nadroparin in patients with cancer-associated VTE. Consecutive patients with active cancer and objectively confirmed VTE, treated at a Dutch or a Spanish hospital, were followed during LMWH therapy with a maximum of 180 days. Cumulative incidences of discontinuation of both LMWHs were estimated and compared according to the Kaplan-Meier method, applying a competing risk analysis to correct for mortality. A total of 366 patients were analyzed during LMWH treatment, of whom 284 patients (78%) were treated with enoxaparin and 82 (22%) with nadroparin. The cumulative incidence of discontinuation of enoxaparin and nadroparin treatment because of side effects was 30% (95% confidence interval [CI] 24–36) and 8.8% (95% CI 1.1–15), respectively. Competing risk analysis revealed a higher number of patients discontinuing enoxaparin due to side effects (adjusted hazard ratio [HR]: 2.8; 95% CI 1.06–7.2). Pain at the injection site was the most common reason of discontinuation in patients using enoxaparin, occurring in 32 patients, while it occurred in 1 patient using nadroparin (adjusted HR: 4.0; 95% CI 0.52–31). This analysis reveals that enoxaparin was associated with a higher risk of discontinuation because of side effects compared to nadroparin. However, given the nature of the patient groups, these findings should be followed by future studies.

Delayed-onset heparin-induced skin necrosis: a rare complication of perioperative heparin therapy

An uncommon case of delayed-onset dalteparin-induced skin necrosis in an 83-year-old Caucasian female patient associated with heparin-induced thrombocytopaenia (HIT) presenting on day 30 following dalteparin therapy is reported. Investigations revealed mild thrombocytopaenia with normal protein C, protein S, coagulation screen and positive test for heparin-platelet factor-4 antibody. Clinical diagnosis of heparin-induced skin necrosis with HIT was made. Dalteparin injection was discontinued promptly and substituted with fondaparinux therapy. The patient achieved good recovery following cessation of dalteparin therapy and was subsequently discharged.

Consequences of Venous Thromboembolism, Including Chronic Thromboembolic Pulmonary Hypertension

Venous thromboembolism includes both deep vein thrombosis and pulmonary embolism. They pose a significant risk for morbidity and mortality. In an appropriate clinical setting, invasive interventions, including administration of thrombolytics, anticoagulation, and placement of vena cava filter, are warranted. Bleeding, postthrombotic syndrome, recurrence, and filter-associated complications are few of the complications of this disease. More recently, chronic thromboembolic pulmonary hypertension has gained clinical interest in patients with pulmonary embolism and has warranted close follow-up.

Pharmacology of Heparin and Related Drugs

Heparin has been recognized as a valuable anticoagulant and antithrombotic for several decades and is still widely used in clinical practice for a variety of indications. The anticoagulant activity of heparin is mainly attributable to the action of a specific pentasaccharide sequence that acts in concert with antithrombin, a plasma coagulation factor inhibitor. This observation has led to the development of synthetic heparin mimetics for clinical use. However, it is increasingly recognized that heparin has many other pharmacological properties, including but not limited to antiviral, anti-inflammatory, and antimetastatic actions. Many of these activities are independent of its anticoagulant activity, although the mechanisms of these other activities are currently less well defined. Nonetheless, heparin is being exploited for clinical uses beyond anticoagulation and developed for a wide range of clinical disorders. This article provides a "state of the art" review of our current understanding of the pharmacology of heparin and related drugs and an overview of the status of development of such drugs.

Bullous hemorrhagic dermatosis induced by enoxaparin

The bullous hemorrhagic dermatosis induced by enoxaparin is a rare adverse reaction, which may be under-reported given its favorable evolution. We report a 71-year-old man who developed hemorrhagic bullae at sites distant from subcutaneous enoxaparin injections. It is important that clinicians be aware of the different adverse reactions of these widely used drugs.

Effect of subcutaneous Enoxaparin injection duration on bruising size in acute coronary syndrome patients

BACKGROUND

Bruising is an unpleasant result of subcutaneous injection of Enoxaparin, which causes physical discomfort, limitation of injection site, patient's refusal of treatment, and distrust in nurses' ability. The application of techniques which reduce patients' fear, anxiety, and physical damage is one of the tasks of nurses. This clinical trial investigated the effect of duration of subcutaneous Enoxaparin injection on the bruising size in acute coronary syndrome patients.

MATERIALS AND METHODS

Seventy 35-75-year-old acute coronary syndrome patients hospitalized in Coronary Care Units were selected randomly. Each subject received 10- and 30-sec duration of injections by a single researcher on both sides of the abdomen in 12-h intervals. The bruising size was measured using a transparent millimeter measuring paper, 24 and 48 h after each injection. Data were gathered by a data recording form (demographic and measurements data) and analyzed by descriptive statistics and non-parametric tests through SPSS.

RESULTS

Results showed that the mean bruising sizes at 24 h after 10- and 30-sec injection were 33.26 mm(2) (72.77) and 48.96 mm(2) (99.91), respectively, and at 48 h were 15.61 mm(2) (142.02) and 52.48 mm(2) (143), respectively. There was no significant relationship between the two techniques (P > 0.05), although the effect of age on bruising size was significant (P = 0.01).

CONCLUSION

According to the findings of the present study, length of Enoxaparin subcutaneous injection has no effect on the bruising size.

Occurrence and extent of bruising according to duration of administration of subcutaneous low-molecular-weight heparin: a quasi-experimental case-crossover study

BACKGROUND

Several authors have documented the role of low-molecular-weight heparin injection techniques in bruising. However, few researchers have measured the influence of injection duration on the occurrence and extent of bruising.

PURPOSE

The aim of this study was to evaluate the influence of different durations of subcutaneous heparin injection on the occurrence and extent of bruising.

METHODS

A quasi-experimental case-crossover study design was adopted in 2010. A consecutive series of patients admitted to 2 orthopedic units in a large (600 beds) teaching hospital located in northern Italy were eligible for enrolment. Injections were administered following a standard procedure. The manipulated variable was the duration of the injection, 10 seconds (treatment A) and 30 seconds (treatment B). The evaluation of bruise occurrence and extension performed after 48 hours and data analysis were conducted in a blinded fashion.

RESULTS

A total of 150 patients receiving their first and second subcutaneous heparin injections (300 injections) were enrolled. Eighty-seven bruises were observed out of 300 injections (29%): 57 of 150 (38%) after injections lasting 10 seconds and 30 of 150 (20%) after injections lasting 30 seconds (relative risk, 1.50; 95% confidence interval, 1.21-1.86; P = .00). Of the 87 bruises that occurred, 69 (79.3%) were small (2-5 mm) and 18 (20.6%) were large (>5 mm), with no difference in size between 10- and 30-second injections (relative risk, 0.91; 95% confidence interval, 0.39-2.12; P = .83).

CONCLUSIONS

Low-molecular-weight heparin injection should be administered over 30 seconds to decrease bruising.

CLINICAL IMPLICATIONS

There is a need to reflect on the feasibility of such a practice because injecting low-molecular-weight heparin at 30 seconds requires accuracy, a steady hand, the absence of tremor, a calm environment, and the ability to administer an infinitesimally small amount of liquid (eg, 0.4 mL) per second.

Subcutaneous infiltrative nodule at the injection site of low-molecular weight heparin simulating malignancy

Low-molecular weight heparins (LMWHs) are the standard agents used for the prevention and treatment of thromboembolic disorders. Despite their widespread use, reports on adverse effects from LMWHs are uncommon. The present report describes a 23-year-old woman with a 3.8-cm solitary, fibrofatty, poorly demarcated nodule involving the subcutaneous tissue of the infraumbilical abdominal wall that appeared 4 years after iterative local administration of LMWH. Microscopically, the nodule showed atypical cells, with bizarre nuclei in the septa of cellular fibrous tissue dissecting the adipose lobules, in the absence of any other malignant changes. To the best of our knowledge, this kind of LMWH-related lesion has not been previously reported. The lesion may result from the combination of an idiosyncratic reaction to the LMWH with local trauma being a probable promoting factor. Alternatively, this reactive proliferation may be entirely due to the trauma represented by repeated injections. This rare process could easily be confused with liposarcoma. As the clinical history of injections is often not provided in the requisition form, pathologists should be aware of this adverse effect from LMWH to avoid misdiagnosis and excessive treatment.

Recent advances in the diagnosis and treatment of heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a drug-mediated, prothrombotic disorder caused by immunization against platelet factor 4 (PF4) after complex formation with heparin or other polyanions. After their binding to PF4/heparin complexes on the platelet surface, HIT antibodies are capable of intravascular platelet activation by cross-linking Fcγ receptor IIA leading to a platelet count decrease and/or thrombosis. Diagnosis of HIT is often difficult. This, and the low specificity of the commercially available immunoassays, leads currently to substantial overdiagnosis of HIT. Timing of onset, the moderate nature of thrombocytopenia, and the common concurrence of thrombosis are very important factors, which help to differentiate HIT from other potential causes of thrombocytopenia. A combination of a clinical pretest scoring system and laboratory investigation is usually necessary to diagnose HIT. Although HIT is considered to be a rare complication of heparin treatment, the very high number of hospital inpatients, and increasingly also hospital outpatients receiving heparin, still result in a considerable number of patients developing HIT. If HIT occurs, potentially devastating complications such as life-threatening thrombosis make it one of the most serious adverse drug reactions. If HIT is strongly suspected, all heparin must be stopped and an alternative nonheparin anticoagulant started at a therapeutic dose to prevent thromboembolic complications. However, the nonheparin alternative anticoagulants bear a considerable bleeding risk, especially if given to patients with thrombocytopenia due to other reasons than HIT. While established drugs for HIT are disappearing from the market (lepirudin, danaparoid), bivalirudin, fondaparinux and potentially the new anticoagulants such as dabigatran, rivaroxaban and apixaban provide new treatment options.

Heparin-induced skin lesions

Heparins are widely used for prophylaxis and treatment of thromboembolic diseases. Besides bleeding complications, heparin-induced skin lesions are the most frequent unwanted adverse effects of subcutaneous heparin treatment. Evidence suggests that these lesions are more common than previously thought. Lesions are most frequently due to either allergic reactions or to possibly life-threatening heparin-induced thrombocytopenia. Early recognition and adequate treatment are highly important, because although both complications initially show a similar clinical picture, their treatment should be fundamentally different. Furthermore, risk factors associated with the patient, drug, and treatment regimen have been identified. We review the clinical range of heparin-induced skin lesions, emphasise evidence and controversies in epidemiology, diagnosis, and differential diagnosis, and discuss the management of patients with these skin lesions.

A GENS-based approach to cardiovascular pharmacology: impact on metabolism, pharmacokinetics and pharmacodynamics

Pharmacological outcomes depend on many factors, with many of them being sexually dimorphic. Thus, physiological gender/sex (GENS) differences can influence pharmacokinetics, pharmacodynamics and, thus, bioavailability and resulting in efficacy of treatment, meaning GENS differences should be an important consideration in therapeutics. In particular, drug response can change according to different hormonal environments. Therefore, GENS-specific differences have a particular clinical relevance in terms of drug delivery, especially for those substances with a narrow therapeutic margin. Since adverse effects are more frequent among women, safety is a key issue. Overall, the status of women, from a pharmacological point of view, is often different and less studied than that of men and deserves particular attention. Further studies focused on women's responses to drugs are necessary in order to make optimal pharmacotherapeutic decisions.

Adverse effects of heparin

All the adverse effects of heparins are related to their wide variety of biological activities, with bleeding being the most important safety issue, resulting directly from the potency of heparin as an anticoagulant. However, it is hard to define the bleeding risk, since it depends on numerous parameters including the indication, dosage, method, and duration of heparin application, the clinical study design and definition of bleeding as well as patient characteristics and determinants of bleeding such as type of surgery and co-medication. Nonbleeding complications of heparins are caused by binding of heparin molecules to proteins other than antithrombin and to cells, which is generally more pronounced with unfractionated heparin than with low-molecular-weight heparins. Accordingly, heparin-induced thrombocytopenia, the most severe nonbleeding adverse reaction, occurs about 10 times less with low-molecular-weight heparins than with unfractionated heparin. Frequent and therefore important adverse reactions of heparins are skin lesions resulting from delayed-type hypersensitivity reactions. All the other undesirable effects are discussed as well, but they are mostly clinically irrelevant.

Results of a consensus meeting on the use of argatroban in patients with heparin-induced thrombocytopenia requiring antithrombotic therapy - a European Perspective

Argatroban has been introduced as an alternative parenteral anticoagulant for HIT-patients in several European countries in 2005. In 2009 a panel of experts discussed their clinical experience with argatroban balancing risks and benefits of argatroban treatment in managing the highly procoagulant status of HIT-patients. This article summarizes the main conclusions of this round table discussion. An ongoing issue is the appropriate dosing of argatroban in special patient groups. Therefore, dosing recommendations for different HIT-patient groups (ICU patients; non-ICU patients, paediatric patients, and for patients undergoing renal replacement therapies) are summarized in this consensus statement. Because of the strong correlation between argatroban dosing requirements and scores used to characterize the severity of illness (APACHE; SAPS, SOFA) suitable dosing nomograms are given. This consensus statement contributes to clinically relevant information on the appropriate use and monitoring of argatroban based on the current literature, and provides additional information from clinical experience. As the two other approved drugs for HIT, danaparoid and lepirudin are either currently not available due to manufacturing problems (danaparoid) or will be withdrawn from the market in 2012 (lepirudin), this report should guide physicians who have limited experience with argatroban how to use this drug safely in patients with HIT.

Low allergenic potential with fondaparinux: results of a prospective investigation

OBJECTIVE

To determine the incidence and causes of skin reactions to the synthetic pentasaccharide fondaparinux.

PATIENTS AND METHODS

Patients who received prophylactic/therapeutic subcutaneous fondaparinux treatment for more than 7 days were prospectively examined for cutaneous adverse effects between September 1, 2008, and April 30, 2009. When indicated, other procedures, such as skin biopsy, allergy testing, and clinical/laboratory assessment for thrombosis and heparin-induced thrombocytopenia, were performed.

RESULTS

Overall, 231 patients were enrolled. No patient developed typical delayed type IV hypersensitivity (DTH) erythematous skin lesions. However, one female patient experienced abdominal pruritus at sites of injection. Histology revealed a mild lymphohistiocytic infiltrate, confirming a DTH reaction. Heparin-induced thrombocytopenia, as another possible underlying pathomechanism for cutaneous lesions, was ruled out clinically and serologically. Hence, the overall incidence of fondaparinux-induced allergic skin lesions was 0.4% (95% confidence interval, 0.01%-2.4%). No cross-allergies were observed in patients with DTH reaction to heparins.

CONCLUSION

Fondaparinux has a low allergenic potential. The incidence of allergic cutaneous DTH reactions is almost 20 times lower compared to that with commonly used heparins. These results, together with the known low prevalence of secondary thrombotic events or heparin-induced thrombocytopenia during fondaparinux therapy, suggest that in selected patients fondaparinux might substantially improve patient care, therapeutic safety, and cost-effectiveness of anticoagulant therapy.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT00510432.