Induced Thrombocytopenia

Following the fundamental investigations of Ackroyd (Dausset et al. 1964) on Se-dormid-induced thrombocytopenic purpura, numerous publications reported similar effects induced by a large variety of drugs. Several methods have been devized to establish the diagnosis. 

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Arepally GM, Ortel TL (2006) Clinical practice. Heparin-induced thrombocytopenia. N Engl JMed 355 809-817... 

Figure 24.4 The decision-analytic model shows the three strategies that were examined by Arnold and researchers [22] to evaluate the financial implications of the direct thrombin inhibitor argatroban for early treatment (<48 hours after thrombocytopenia onset), compared with delayed treatment, of heparin-induced thrombocytopenia (HIT) with or without thrombosis.

Arnold R, Kim R, Zhou Y, Tang B. Budgetary impact of heparin-induced thrombocytopenia with thrombosis and treatment with the direct thrombin inhibitor Argatroban (P401E). ASHP 39th Midyear Clinical Meeting. Orlando, FL, 2004. 

Arnold R, Kim R, Tang B. The cost-effectiveness of argatroban treatment in heparin-induced thrombocytopenia the effect of early versus delayed treatment. Cardiol Rev 2005 14 7-13. 

Hemorrhage is the main complication that can arise from heparin therapy. Other side effects include Heparin-Induced Thrombocytopenia Syndrome (HITS), local irritation, hypersensitivity reactions and with long-term use, alopecia, hypoaldoster-onism, and osteoporosis. 

Avoid warfarin monotherapy during the acute phase of heparin-induced thrombocytopenia (HIT)... 

Unfractionated heparin Bleeding, heparin-induced thrombocytopenia Clinical signs of bleeding3 baseline CBC and platelet count aPTT every 6 hours until target then every 24 hours daily CBC platelet count every 2 days (minimum, preferably every day)... 

DVT, deep vein thrombosis HIT, heparin-induced thrombocytopenia PAI-I, plasminogen activator inhibitor PE, pulmonary embolism SERM, selective estrogen receptor modulator VTE, venous thromboembolism. 

Heparin-induced thrombocytopenia (HIT) is a very serious adverse effect associated with UFH use. Platelet counts should be monitored every 2 to 3 days dining the course of UFH therapy.5 HIT should be suspected if the platelet count drops by more than 50% from baseline or to below 120,000. In patients with contraindications to anticoagulation therapy, UFH should not be administered (Table 7-7). 

HIT, heparin-induced thrombocytopenia INR, International Normalized Ratio LMWHs, low-molecular-weight heparins PT, prothrombin time UFH, unfractionated heparin. 

If the patient is treated with UFH or LMWH and platelet count has dropped by more than 50% from baseline or is less than 120x1 OVjil, evaluate the patient for heparin-induced thrombocytopenia (HIT). 

HIT heparin-induced thrombocytopenia t-PA tissue plasminogen activator... 

Wazny LD, Ariano RE. Evaluation and management of drug-induced thrombocytopenia in the acutely ill patient. Pharmacotherapy 2000 20(3) 292-307. 

The benefit and necessity of adding heparin to PN are unclear. There are also concerns about the stability/compatibility of intravenous lipid emulsions with heparin added at concentrations above 1 unit/mL. Heparin should be omitted in patients with active bleeding, thrombocytopenia, heparin-induced thrombocytopenia (HIT), or heparin allergy. 

Heparin-induced thrombocytopenia A clinical syndrome of IgG antibody production against the heparin-platelet factor 4 complex occurring in approximately 1% to 5% of patients exposed to either heparin or low-molecular-weight heparin. Heparin-induced thrombocytopenia results in excess production of thrombin, platelet aggregation, and thrombocytopenia (due to platelet clumping), often leading to venous and arterial thrombosis, amputation of extremities, and death. 

Neumega Oprelvekin Genetics Institute Prevention of severe chemotherapy-induced thrombocytopenia... 

Refludan Lepirudin Hoechst Marion Roussel Heparin-induced thrombocytopenia type II... 

Prophylaxis -can be used in heparin-induced thrombocytopenia Lepirudin 0.1 mg/kg/hr... 

J Heparin-induced thrombocytopenia (HIT) is a serious immune-mediated problem that requires immediate intervention. For patients receiving therapeutic UFH doses, a baseline platelet count should be obtained before therapy is initiated and then every-other-day for 14 days or until therapy is stopped, whichever occurs first. HIT should be suspected if a patient develops a thromboembolic event (e.g., DVT, PE, stroke, myocardial infarction, limb artery occlusion) during or soon after receiving UFH. The platelet... 

Severe thrombocytopenia and reduction of the need for platelet transfusions Chemotherapy-induced thrombocytopenia Nov. 1997... 

Franchini, M, Heparin-induced thrombocytopenia An update, Thrombosis, 3, 14, 2005. 

The antagonistic properties of FR 900452 have also been examined in a model of endotoxin shock, the haemodynamic and haematological manifestations of this condition closely resembling the changes induced by PAF. FR 900452 (10 mg/kg, i.v.) almost completely prevents PAF (1 /ig/kg, i.v.)-induced thrombocytopenia and leukocytopenia in rabbits [295]. It also significantly inhibits endotoxin (E. coli LPS, 30 /ig/kg, i.v.)-induced thrombocytopenia but not leukocytopenia. The same dose of FR 900452 also causes the decreased arterial blood pressure to return to normal in the endotoxin-induced rat hypotension model, an effect also reported for other PAF inhibitors [121, 274], Finally, FR 900452 has been tested for its therapeutic effect on rat nephrosis induced by aminonucleoside (puromycin, 100 mg/kg, i.p.). At 100 mg/kg twice a day orally for 6 days, the agent significantly reduces urinary protein loss in nephrotic rats [298]. 

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