Background and Objectives: HEPARIN is still a commonly used anticoagulant in prophylaxis and treatment of thromboembolic events. HEPARIN-induced thrombocytopenia (HIT) is a life-threating adverse drug reaction of HEPARIN. The diagnosis of HIT is made based on two important criteria, firstly clinical evaluation and secondly laboratory testing. In this comprehensive review, the authors will emphasize the risk factors, clinical presentation, pathophysiology, diagnostic principals and treatment of HIT. Materials and Methods: Our study method was based on the search in the PubMed Database by related key words like: "HEPARIN", "HEPARIN induced thrombocytopenia", "pathophysiology", "diagnosis" and “ treatment” published during 1997 to 2018. Results: The disease is still a life-threatening event caused by the creation of an antibody against the HEPARIN-PF4 complex and, if platelets are activated, can lead to thrombotic events in patients. Laboratory diagnostic methods are important in excluding or confirming the diagnosis of HIT, especially in patients who are moderate or highly clinical probability of HIT suspected. Conclusions: Today, with a better understanding of the pathophysiology of the disease as well as the advances made in the speed and precision of laboratory diagnostic methods, an important development has occurred in the diagnosis of HIT.

Background: In spite of using anticoagulant drugs such as unfractionated HEPARIN (UFH) and low molecular weight HEPARIN (LMWH) in the treatment of acute ischemic stroke, the efficacy of them has not been documented. Regarding to the frequent administration of these drugs, the evaluation of efficacy, advantages, and hazard of them is much important.Methods: We reviewed articles about this type of treatment including randomized clinical trials, meta-analyses, original articles, systematic reviews and review articles published in MEDLINE and EMBASE during 1997-2003.Results: In the short- and long- term follow up, UFH and LMWH don't result in considerable decreasing mortality, progression of stroke and early relapse risk. They don't result in considerable improvement in clinical and functional status of patients. In spite of considerable decreasing of deep vein thrombosis (DVT) and pulmonary emboli (PE) by administration of UFH and LMWH, it is established that they increase risk of intra- or hemorrhage. There is no valid document that immediate administration of anticoagulants (particularly intravenous and high dose) has helpful outcome. Conclusion: UFH and LMWH are not recommended in the majority of cases with stroke particularly during the first 24-48 hours of attach. Subcutaneous administration of UFH and LMWH is helpful in preventing DVT and PE, while they increase risk of systemic and intracranial hemorrhages. Immediate treatment is not recommended in any type of cerebrovascular accident (CVA).

Background: Low Molecular Weight HEPARINs (LMWH) are an important new class of antithrombotic agents. They differ from Unfractionated HEPARIN (UFH) in having relatively more anti-Xa activity, and greater bioavailability at low doses. Larger half life allows us to use it as a single dose therapy. Beneficial effect on dyslipidemia of hemodialysis also was noted. In this research we evaluated the efficacy of LMW HEPARIN, fragmin, on Partial Thromboplastin Time (PTT) during hemodialysis anticoagulation in comparison with UFH to recognize the rate of disturbance on PTT and its effect on dialysis adequacy.Subject and methods: This research was done in two steps, first with commercial HEPARIN, on 30 patients, by controlling PTT before, at first half an hour and at the end of dialysis session (three sample). At second step with fragmin and on 35 patients, sampling were the same. Also dialysis adequacy was measured by Urea Reduction Rate (URR) formula, and compared with dialysis adequacy of previous session. The desired URR is over 65%, so we divided the patients into two groups of over 65% and below 65% and then we analysed the datas.Result: Analysing the datas showed that at first half and hour of hemodialysis the result of PTT disturbance with low-molecular weight HEPARIN was better (better anticoagulation), but at the end of dialysis there were no differences between two methods of anticoagulation. No significant association determined by the chi-square test.Conclusion: Comparing the dialysis adequacy with fragmin and unfractionated HEPARIN showed no difference and as a result, fragmin can induce an equal dialysis adequacy by inducing an adequate anticoagulation.