Use of a low-molecular-weight heparinoid (danaparoid sodium) for continuous renal replacement therapy in intensive care patients

Danaparoid-Consensus Recommendations on Its Clinical Use

(1) Background: Danaparoid sodium is a heparinoid antithrombotic that has been used for over 40 years for prophylaxis of DVT in non-HIT patients and for the treatment of heparin-induced thrombocytopenia (HIT) with and without thrombosis. This update summarises current information on its pharmacology and reviews danaparoid dose management in a broad spectrum of clinical situations, including off-label indications. (2) Methods: Evidence from published clinical studies, case reports, compassionate use of danaparoid, and spontaneously reported serious adverse events is summarised and analysed by an interdisciplinary expert group to develop a consensus on dosing regimens of danaparoid for complex clinical situations, including vulnerable patient populations. (3) Results: Dosing regimens are proposed, together with monitoring recommendations and target anti-factor Xa ranges. (4) Conclusion: In a comprehensive summary detailed interdisciplinary dosing recommendations are described to provide a basis for safe and effective use of danaparoid.

Comparative effectiveness and safety of anticoagulants for the treatment of heparin-induced thrombocytopenia

BACKGROUND

The effectiveness and safety of non-heparin anticoagulants for the treatment of heparin-induced thrombocytopenia (HIT) are not fully established, and the optimal treatment strategy is unknown. In a systematic review and meta-analysis, we aimed to determine precise rates of platelet recovery, new or progressive thromboembolism (TE), major bleeding, and death for all non-heparin anticoagulants and to study potential sources of variability.

METHODS

Following a detailed protocol (PROSPERO: CRD42020219027), EMBASE and Medline were searched for all studies reporting clinical outcomes of patients treated with non-heparin anticoagulants (argatroban, danaparoid, fondaparinux, direct oral anticoagulants [DOAC], bivalirudin, and other hirudins) for acute HIT. Proportions of patients with the outcomes of interest were pooled using a random-effects model for each drug. The influence of the patient population, the diagnostic test used, the study design, and the type of article was assessed.

RESULTS

Out of 3194 articles screened, 92 studies with 119 treatment groups describing 4698 patients were included. The pooled rates of platelet recovery ranged from 74% (bivalirudin) to 99% (fondaparinux), TE from 1% (fondaparinux) to 7% (danaparoid), major bleeding from 1% (DOAC) to 14% (bivalirudin), and death from 7% (fondaparinux) to 19% (bivalirudin). Confidence intervals were mostly overlapping, and results were not influenced by patient population, diagnostic test used, study design, or type of article.

DISCUSSION

Effectiveness and safety outcomes were similar among various anticoagulants, and significant factors affecting these outcomes were not identified. These findings support fondaparinux and DOACs as viable alternatives to conventional anticoagulants for treatment of acute HIT in clinical practice.

Management of heparin-induced thrombocytopenia: systematic reviews and meta-analyses

Heparin-induced thrombocytopenia (HIT) is a prothrombotic adverse drug reaction occurring in <0.1% to 7% of patients receiving heparin products depending on the patient population and type of heparin. Management of HIT is highly dependent on a sequence of tests for which clinicians may or may not have the results when care decisions need to be made. We conducted systematic reviews of the effects of management strategies in persons with acute HIT, subacute HIT A or B, and remote HIT. We searched Medline, EMBASE, and the Cochrane Database through July 2019 for previously published systematic reviews and primary studies. Two investigators independently screened and extracted data and assessed the certainty of the evidence using the Grading of Recommendations Assessment, Development and Evaluation approach. We found primarily noncomparative studies and case series assessing effects of treatments, which led to low to very low certainty evidence. There may be little to no difference in the effects between nonheparin parenteral anticoagulants and direct oral anticoagulants in acute HIT. The benefits of therapeutic-intensity may be greater than prophylactic-intensity anticoagulation. Using inferior vena cava filters or platelet transfusion may result in greater harm than not using these approaches. Evidence for management in special situations, such as for patients undergoing cardiovascular interventions or renal replacement therapy, was also low to very low certainty. Additional research to evaluate nonheparin anticoagulants is urgently needed, and the development of novel treatments that reduce thrombosis without increasing hemorrhage should be a priority.

Pharmacological Agents Targeting Thromboinflammation in COVID-19: Review and Implications for Future Research

Coronavirus disease 2019 (COVID-19), currently a worldwide pandemic, is a viral illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The suspected contribution of thrombotic events to morbidity and mortality in COVID-19 patients has prompted a search for novel potential options for preventing COVID-19-associated thrombotic disease. In this article by the Global COVID-19 Thrombosis Collaborative Group, we describe novel dosing approaches for commonly used antithrombotic agents (especially heparin-based regimens) and the potential use of less widely used antithrombotic drugs in the absence of confirmed thrombosis. Although these therapies may have direct antithrombotic effects, other mechanisms of action, including anti-inflammatory or antiviral effects, have been postulated. Based on survey results from this group of authors, we suggest research priorities for specific agents and subgroups of patients with COVID-19. Further, we review other agents, including immunomodulators, that may have antithrombotic properties. It is our hope that the present document will encourage and stimulate future prospective studies and randomized trials to study the safety, efficacy, and optimal use of these agents for prevention or management of thrombosis in COVID-19.

Renal Replacement Therapy in the Critical Care Setting

Renal replacement therapy (RRT) is frequently required to manage critically ill patients with acute kidney injury (AKI). There is limited evidence to support the current practice of RRT in intensive care units (ICUs). Recently published randomized control trials (RCTs) have further questioned our understanding of RRT in critical care. The optimal timing and dosing continues to be debatable; however, current evidence suggests delayed strategy with less intensive dosing when utilising RRT. Various modes of RRT are complementary to each other with no definite benefits to mortality or renal function preservation. Choice of anticoagulation remains regional citrate anticoagulation in continuous renal replacement therapy (CRRT) with lower bleeding risk when compared with heparin. RRT can be used to support resistant cardiac failure, but evolving therapies such as haemoperfusion are currently not recommended in sepsis.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia

BACKGROUND

Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction mediated by platelet-activating antibodies that target complexes of platelet factor 4 and heparin. Patients are at markedly increased risk of thromboembolism.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians, and other health care professionals in their decisions about diagnosis and management of HIT.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 33 recommendations. The recommendations address screening of asymptomatic patients for HIT, diagnosis and initial management of patients with suspected HIT, treatment of acute HIT, and special situations in patients with acute HIT or a history of HIT, including cardiovascular surgery, percutaneous cardiovascular intervention, renal replacement therapy, and venous thromboembolism prophylaxis.

CONCLUSIONS

Strong recommendations include use of the 4Ts score rather than a gestalt approach for estimating the pretest probability of HIT and avoidance of HIT laboratory testing and empiric treatment of HIT in patients with a low-probability 4Ts score. Conditional recommendations include the choice among non-heparin anticoagulants (argatroban, bivalirudin, danaparoid, fondaparinux, direct oral anticoagulants) for treatment of acute HIT.

Renal replacement therapy in acute kidney injury: controversy and consensus

Renal replacement therapies (RRTs) represent a cornerstone in the management of severe acute kidney injury. This area of intensive care and nephrology has undergone significant improvement and evolution in recent years. Continuous RRTs have been a major focus of new technological and treatment strategies. RRT is being used increasingly in the intensive care unit, not only for renal indications but also for other organ-supportive strategies. Several aspects related to RRT are now well established, but others remain controversial. In this review, we review the available RRT modalities, covering technical and clinical aspects. We discuss several controversial issues, provide some practical recommendations, and where possible suggest a research agenda for the future.

Argatroban for anticoagulation in continuous renal replacement therapy

OBJECTIVE

Argatroban, a direct thrombin inhibitor, was evaluated for anticoagulation in continuous renal replacement therapy (CRRT) in critically ill patients with heparin-induced thrombocytopenia type II and acute renal failure. The investigation focused on predictors for the maintenance doses of argatroban with efficacy and safety of argatroban being secondary outcomes.

DESIGN

Prospective, dose finding study.

SETTING

Two intensive care units (medical and surgical) of a university hospital.

PATIENTS

Medical and surgical patients (n = 30) with acute or histories of heparin-induced thrombocytopenia type II and acute renal failure with necessity for CRRT.

INTERVENTION

CRRT with argatroban for anticoagulation.

MEASUREMENTS AND MAIN RESULTS

Critical illness severity scores Acute Physiology and Chronic Health Evaluation (APACHE)-II, Simplified Acute Physiology Score (SAPS) II, and the indocyanine green plasma disappearance rate (ICG-PDR) were correlated to the argatroban maintenance doses. These diagnostic tools can help to identify patients with the necessity for decreased argatroban doses. The following recommendations for argatroban dosing during CRRT could be determined: a loading dose of 100 microg/kg followed by a maintenance infusion rate (microg/kg/min), which can be calculated from the scores as follows: for APACHE II: 2.15-0.06 x APACHE II (r = -.81, p < 0.001); for SAPS II: 2.06-0.03 x SAPS II (r = -.8, p < 0.001); and for ICG-PDR: -0.35 + 0.08 x ICG-PDR (r = .89, p < 0.001). The efficacy and safety of anticoagulation during CRRT were determined by the steady state of blood urea nitrogen (32.16 +/- 18.02 mg/dL), mean filter patency at 24 hrs (98%), and the rate of bleeding episodes. Only two patients developed minor bleeding; no patient developed severe bleeding episodes.

CONCLUSION

In critically ill patients with heparin-induced thrombocytopenia type II and necessity for CRRT critical illness scores (APACHE II, SAPS II) or ICG-PDR can help to predict the required argatroban maintenance dose for anticoagulation. These predictors identify decreased argatroban dosing requirements resulting in effective and safe CRRT.

Role of citrate and other methods of anticoagulation in patients with severe liver failure requiring continuous renal replacement therapy

Anticoagulation is required during continuous renal replacement therapy to prevent filter clotting and optimize filter performance. However, anticoagulation may also be associated with serious bleeding complications. Patients with liver failure often suffer from underlying coagulopathy and are especially prone to anticoagulation complications. The aim of this review is to present the unique features of patients with hepatic injury in terms of anticoagulation disorders and to analyze data on safety and efficacy of the different anticoagulation methods for liver failure patients undergoing continuous renal replacement therapy.

Pharmacokinetics and pharmacodynamics of danaparoid during continuous venovenous hemofiltration: a pilot study

Background

In patients with suspected heparin-induced thrombocytopenia (HIT) who need renal replacement therapy, a nonheparin anticoagulant has to be chosen to prevent thrombosis in the extracorporeal circuit. Danaparoid, a low-molecular-weight heparinoid consisting of heparan sulphate, dermatan sulphate, and chondroitin sulphate, is recommended for systemic anticoagulation in patients with HIT. However, there are few data on the use of danaparoid in patients with acute renal failure, especially in patients dependent on renal replacement therapy such as continuous venovenous hemofiltration (CVVH). In the present study, we analyzed the pharmacokinetics and pharmacodynamics of danaparoid during CVVH in patients with suspected HIT.

Methods

Based on a mathematical model, a dosing scheme for danaparoid was designed, aiming at anti-Xa levels of 0.5 to 0.7 U/mL, with a maximum of 1.0 U/mL. This dosing scheme was prospectively tested in the first CVVH run of a cohort of five patients with suspected HIT. CVVH with a blood flow rate of 150 mL/minute and a substitution rate of 2,000 mL/hour was performed with a cellulose triacetate membrane. Danaparoid was administered as a continuous infusion of 100 anti-Xa-U/hour after a loading dose of 3,500 anti-Xa-U. Serial measurements of anti-Xa activity and prothrombin fragment F1+2 were performed at baseline, at t = 5, 15, and 30 minutes, and at t = 1, 2, 4, 8, 16, and 24 hours after the danaparoid loading dose.

Results

The median anti-Xa activity reached a maximum of 1.02 (0.66 to 1.31) anti-Xa-U/mL after 15 minutes and gradually declined to 0.40 (0.15 to 0.58) anti-Xa-U/mL over the span of 24 hours. Target anti-Xa levels were reached from 2 to 12 hours after the loading dose. Median prothrombin fragment F1+2 gradually decreased from 432 (200 to 768) to 262 (248 to 317) pmol/L after 24 hours. No bleeding or thromboembolic events occurred throughout the described treatment period.

Conclusion

Danaparoid administered by a continuous infusion of 100 anti-Xa-U/hour after a loading dose of 3,500 anti-Xa-U elicited target anti-Xa levels from 2 to 12 hours after the loading dose, without bleeding or thromboembolic events during the described CVVH treatment in patients with suspected HIT.

Management of Uremic Patients With Heparin-Induced Thrombocytopenia Requiring Hemodialysis

Medical records of 122 patients with suspected heparin-induced thrombocytopenia on dialysis were reviewed. Method of dialysis in heparin-induced thrombocytopenia patients with bleeding from various causes (including surgical interventions) and how to cope with blood access occlusion induced by heparin-induced thrombocytopenia were studied. Of 122 patients, 17 who met the criteria of >30% thrombocytopenia, clots in the extracorporeal circulation, positive for heparin/PF4 complex antibodies, and improvement from heparin-induced thrombocytopenia with the use of an alternative anticoagulant or another strategy for heparin-induced thrombocytopenia were chosen. Argatroban was uneventfully introduced in 12 patients having neither bleeding nor blood access failure. In all, 2 of 5 patients were treated with peritoneal dialysis. The others requiring a regional anticoagulant were given nafamostat mesilate. Argatroban as an alternative provides effectively anticoagulation in patients with heparin-induced thrombocytopenia on dialysis. In patients with heparin-induced thrombocytopenia with bleeding and its associated risk, nafamostat mesilate was an alternative. Peritoneal dialysis also was applied in cases of blood access failure due to heparin-induced thrombocytopenia.

Anticoagulation in CRRT: Agents and strategies in Australian ICUs

BACKGROUND

Continuous Renal Replacement Therapy (CRRT) should ideally operate with as little interruption as possible. The majority of circuit terminations occur due to clotting. The Longevity of CRRT is able to be improved when the extracorporeal circuit is anticoagulated.

AIMS

This article willt focus attention on anticoagulant agents used in Australian intensive care units (ICU) to prevent clotting in the CRRT circuit.

DISCUSSION

Anticoagulants reviewed include unfractionated or standard heparin, regional heparinisation, low-molecular weight heparins and heparinoids, regional citrate, platelet-inhibiting agents (prostacyclin), thrombin antagonists (recombinant hirudin) and therapy with no anticoagulant use. Each type of anticoagulant was reviewed for mode of action, the method of delivery and how the effect is monitored. Circuit life and the incidence of bleeding were considered as the principle end points in selecting therapy, as well as side-effects with administration such as metabolic disturbances, contraindications to use including allergy and ease of use in the clinical environment.

CONCLUSION

No approach to anticoagulation has yet been reported to be as successful in extending circuit life, whilst remaining inexpensive, easy to manage and easy to reverse, as unfractionated heparin. Certain patient conditions may preclude the use of heparin, such as heparin-induced thrombocytopenia (HIT); then heparinoids, thrombin antagonists and sodium citrate are suggested as alternatives. Regional citrate reduces haemorrhagic complications in patients who have coagulation disorders or are at risk of bleeding. Clinical experience with various agents and strategies should also influence choice. The option of no anticoagulant may be appropriate in selected patients rather than more expensive and less familiar drugs.

Anticoagulation strategies in continuous renal replacement therapy: can the choice be evidence based?

OBJECTIVES

Critical illness increases the tendency to both coagulation and bleeding, complicating anticoagulation for continuous renal replacement therapy (CRRT). We analyzed strategies for anticoagulation in CRRT concerning implementation, efficacy and safety to provide evidence-based recommendations for clinical practice.

METHODS

We carried out a systematic review of the literature published before June 2005. Studies were rated at five levels to create recommendation grades from A to E, A being the highest. Grades are labeled with minus if the study design was limited by size or comparability of groups. Data extracted were those on implementation, efficacy (circuit survival), safety (bleeding) and monitoring of anticoagulation.

RESULTS

Due to the quality of the studies recommendation grades are low. If bleeding risk is not increased, unfractionated heparin (activated partial thromboplastin time, APTT, 1-1.4 times normal) or low molecular weight heparin (anti-Xa 0.25-0.35 IU/l) are recommended (grade E). If facilities are adequate, regional anticoagulation with citrate may be preferred (grade C). If bleeding risk is increased, anticoagulation with citrate is recommended (grade D(-)). CRRT without anticoagulation can be considered when coagulopathy is present (grade D(-)). If clotting tendency is increased predilution or the addition of prostaglandins to heparin may be helpful (grade C(-)).

CONCLUSION

Anticoagulation for CRRT must be tailored to patient characteristics and local facilities. The implementation of regional anticoagulation with citrate is worthwhile to reduce bleeding risk. Future trials should be randomized and should have sufficient power and well defined endpoints to compensate for the complexity of critical illness-related pro- and anticoagulant forces. An international consensus to define clinical endpoints is advocated.

Regional Citrate Anticoagulation in Continuous Hemodialysis – Acid-Base and Electrolyte Balance at an Increased Dose of Dialysis

BACKGROUND

Citrate anticoagulation is an excellent alternative to heparin anticoagulation for patients at high risk of bleeding requiring continuous renal replacement therapy. However, citrate anticoagulation has some potential adverse effects such as metabolic alkalosis and acidosis, hypernatremia, hypo- and hypercalcemia. Thus, most citrate anticoagulation protocols use specially designed dialysis fluids to compensate for most of these disarrangements. This study aimed at establishing a citrate anticoagulation protocol designed for a dialysate flow rate of about 2 l/h.

METHODS

Based on theoretical considerations we composed a dialysis fluid suitable for a 2 l/h dialysis flow rate. The dialysate contained 133 mmol/l sodium, 2 mmol/l potassium, 1.1 mmol/l magnesium, 25 mmol/l lactate, and 112.2 mmol/l chloride.

RESULTS

Twenty-three patients were included in the study. During the treatments minor flow rate adaptations were needed and the treatments were well tolerated. Filter life was appropriate (51.3 +/- 24.6 h). Thirteen patients developed a mild metabolic alkalosis (pH > 7.45 plus BE > +3) which was easily counteracted by increasing the dialysis fluid flow (by increments of 500 ml). Acid-base values returned to normal within 24 h after increasing the dialysate flow. The maximum dialysate flow was 3,000 ml/h. Hypernatremia and hypocalcemia were not observed. The systemic ionized calcium concentration was successfully controlled by adjustments of a continuous calcium infusion made with respect to the results of 6-hourly measurements.

CONCLUSION

The analyzed citrate anticoagulation protocol was well tolerated and filter lifetime was appropriate. Regional anticoagulation with trisodium citrate in combination with a customized calcium-free dialysate is a safe and effective alternative to a heparin-based anticoagulation regimen.

The Management of Patients With Heparin-Induced Thrombocytopenia Who Require Anticoagulant Therapy

For patients with heparin-induced thrombocytopenia (HIT), reexposure to heparin is generally not recommended. However, these patients are likely to require anticoagulation therapy at some point in the future. During acute HIT, when thrombocytopenia and anti-heparin-platelet factor 4 antibodies (or HIT antibodies) are present, therapy with heparin must be avoided. In patients with subacute HIT, when platelets have recovered but HIT antibodies are still present, therapy with heparin should be avoided. In patients with a remote history of HIT, when HIT antibodies have cleared, heparin reexposure may be safe, although recurrent HIT has been described in some patients. For all of these patients, the use of alternate anticoagulant agents, including direct thrombin inhibitors and anti-Xa agents, is preferable. There is an increasing amount of data supporting the use of these alternative agents in a wide variety of clinical circumstances, including thromboprophylaxis and treatment of acute thrombosis. Except for a few clinical situations, it is generally possible to avoid heparin reexposure in patients with a history of HIT.

Don’t miss HIT (heparin induced thrombocytopenia)

Thrombocytopenia following a burn injury can cause serious complications. There are several possible causes including the burn itself, drugs, sepsis and disseminated intravascular coagulation (DIC). A case report of a patient who developed heparin induced thrombocytopenia (HIT) whilst on haemofiltration for acute renal failure is presented. The aetiology of thrombocytopenia in a burns patient and its management is discussed. The key to effective treatment of thrombocytopenia is identification of the cause. HIT is an important diagnosis to include in the differential.

Argatroban for heparin-induced thrombocytopenia in hepato-renal failure and CVVHD

OBJECTIVE

To report a case of significant hepatic and renal failure with the use of argatroban in a patient with heparin-induced thrombocytopenia (HIT) requiring continuous veno-veno hemodialysis (CVVHD).

CASE SUMMARY

A 37-year-old Hispanic man with diabetes mellitus, ethanol abuse, and recent crank use developed a venous thrombosis and possible pulmonary embolism, followed by acute liver and renal failure requiring continuous veno-venous hemofiltration. After several days of heparin therapy, the dialyzer circuit thrombosed and the platelet count decreased to 82 x 10(3)/mm(3). Antibodies for HIT by enzyme-linked immunosorbent assay were positive. Heparin was discontinued, and an argatroban infusion was initiated. After 39 hours on argatroban, the infusion was stopped when minor bleeding was observed with a concurrent activated partial thromboplastin time (aPTT) of 100 seconds. The dialyzer circuit did not clot during the argatroban infusion and did not apparently influence dose-related aPTT measurements. Several days were required for the aPTT to decrease after stopping the argatroban infusion. Fresh frozen plasma had no apparent effect on aPTT values.

DISCUSSION

Several different agents are currently available to provide effective anticoagulation in patients who have immune- mediated HIT. Argatroban is hepatically cleared and may be the preferred direct thrombin inhibitor in the presence of significant renal impairment, but conversely has prolonged effects in hepatic failure. Limited data are available regarding use of direct thrombin inhibitors in patients who have severe hepatic impairment with concurrent renal failure requiring CVVHD. Scant data are available regarding the effect of hemodialysis on the elimination of argatroban.

CONCLUSIONS

The optimal anticoagulant for use in a patient with HIT and concurrent hepatic and renal failure is unclear. No direct thrombin inhibitor has a proven advantage; therefore, selection may depend on clinical factors. Dosing in these patients requires very careful management.

Danaparoid: a review of its use in thromboembolic and coagulation disorders

Danaparoid (danaparoid sodium) is a low molecular weight heparinoid which has undergone clinical study for use as continued anticoagulant therapy in patients with heparin-induced thrombocytopenia (HIT), for the prophylaxis and treatment of deep vein thrombosis (DVT), and for the treatment of disseminated intravascular coagulation (DIC). A nonblind study in patients with HIT has reported that complete clinical resolution is significantly more likely in patients receiving danaparoid than in patients receiving dextran 70. In addition, retrospective analyses and noncomparative data support the use of danaparoid for continued anticoagulant therapy in patients with HIT. Studies in patients undergoing hip surgery have shown that danaparoid significantly reduces the incidence of postoperative DVT compared with aspirin, warfarin, dextran 70 and heparin-dihydroergotamine, while additional data suggest no difference between danaparoid, enoxaparin and dalteparin. In patients undergoing abdominal or thoracic surgery for removal of a malignancy, danaparoid reduced the incidence of postoperative DVT compared with placebo, but showed no significant difference when compared with unfractionated heparin (UFH). Two studies have compared danaparoid with UFH in the prophylaxis of DVT following acute ischaemic stroke; twice daily danaparoid was significantly superior to UFH whereas there was no significant difference between a once-daily dosage and UFH. Danaparoid did not differ from UFH in terms of efficacy in the treatment of existing DVT. In all comparative studies examining the efficacy of danaparoid in the prophylaxis or treatment of DVT (versus warfarin, dextran 70, enoxaparin, dalteparin, aspirin, heparin-dihydroergotamine, UFH and placebo), the incidence of haemorrhagic complications did not differ between treatment groups. In patients with DIC, 61.9% of those patients receiving danaparoid experienced either disappearance or reduction of symptoms of DIC whereas 62% of those receiving UFH showed either no change or aggravation of their symptoms. There was no significant difference between treatment groups in tolerability or overall improvement of DIC.

CONCLUSIONS

Danaparoid is an effective anticoagulant agent which has undergone clinical evaluation in a wide range of disease indications. Current guidelines support the use of danaparoid in prophylaxis of DVT following ischaemic stroke, and in patients who develop HIT. Danaparoid has shown efficacy in DIC, and for DVT prophylaxis in patients undergoing hip surgery although further data are required to establish the role of danaparoid in these indications. In particular, double-blind trials comparing danaparoid with such recommended therapies as the low molecular weight heparins will provide more definitive data on the place of danaparoid in the clinical management of these conditions and ultimately lead to improved patient outcomes.

New Treatment Options for Heparin-Induced Thrombocytopenia

Heparin, in various forms, is used in a variety of conditions including prophylaxis and treatment of thromboembolic disorders. Although the most common adverse effect related to the use of heparin is bleeding, heparin-induced thrombocytopenia (HIT) can also occur. Two types of HIT exist, HIT type I and type II. HIT type I is a mild and self-limiting disease in which the patient’s platelet count may decrease slightly but will recover with continued treatment. This is in contrast to HIT type II, which may lead to potentially devastating complications. Patients with HIT type II are at increased risk for thromboembolic complications that are mediated through autoimmune reactions and therefore require anticoagulation with danaparoid or one of the direct thrombin inhibitors, including lepirudin, argatroban, or bivalirudin. Limited data are available on the use of these agents in special populations including patients who are pregnant or those undergoing procedures such as percutaneous coronary intervention, cardiopulmonary bypass and dialysis, and pregnancy. Future therapies may include the use of unfractionated heparin in combination with glycoprotein IIb/IIIa inhibitors during cardiopulmonary bypass.