Essential thrombocytosis medical therapy
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Essential thrombocytosis Microchapters |
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Differentiating Essential thrombocytosis from other Diseases |
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Diagnosis |
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Treatment |
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Essential thrombocytosis medical therapy On the Web |
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Risk calculators and risk factors for Essential thrombocytosis medical therapy |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]Associate Editor(s)-in-Chief: Soujanya Thummathati, MBBS [2]
Overview
Most of the patients with essential thrombocytosis are asymptomatic and do not require treatment. Patients are usually diagnosed with ET on routine testing for other conditions. Low risk patients are placed on low dose aspirin therapy to lower the risk of thrombosis. Old age, previous history of bleeding or thrombosis, or very high platelet count are considered to be high risk factors and need medical therapy. Hydroxyurea, interferon-α and anagrelide are platelet lowering drugs that may be used in high risk patients. In life threatening cases, emergent plateletpheresis may be done where the blood of a patient is passed through an apparatus that separates out one particular constituent, platelets in this case and returns the remainder to the circulation.[1] Pregnancy in ET patients is associated with a two to three fold increase in risk for spontaneous miscarriage. Close monitoring of the mother for thrombosis as well as placenta is recommended to ensure blood clots are diagnosed in time for interventions.
Medical therapy
- Not all patients need treatment at presentation.
- Low risk patients are placed on low dose aspirin therapy to lower the risk of thrombosis, but there may be an increased risk of bleeding if aspirin is initiated whilst the platelet count is very high or if the patient is predisposed to gastrointestinal bleeds.[2] In the latter cases, aspirin is withheld.
- In those who are at increased risk of thrombosis or bleeding (older age, prior history of bleeding or thrombosis, or very high platelet count), reduction of the platelet count to the normal range can be achieved using hydroxyurea (also known as hydroxycarbamide), interferon-α or anagrelide.
- Low-dose aspirin is widely used to reduce the risk of thrombosis,
- The PT1 study [3] compared hydroxyurea in combination with aspirin to anagrelide in combination with Aspirin as initial therapy for essential thrombocytosis. Hydroxyurea was superior, with lower risk of arterial thrombosis, lower risk of severe bleeding and lower risk of transformation to myelofibrosis (although the rate of venous thrombosis was higher with hydroxycarbamide than with anagrelide).
- In rare cases where patients have life-threatening complications, the platelet count can be reduced rapidly using platelet apheresis (a procedure that removes platelets from the blood directly).
- Pregnacy in ET patients is associated with a two to three fold increase in risk for spontaneous micarriage.
- Hydroxyrea and anagrelide are contraindicated during pregnancy and nursing.[4] There is current debate as to the safety of interferon during pregnancy and nursing.
- Essential thrombocytosis can be linked with increased risk of spontaneous abortion or miscarriage in the first trimester of pregnancy. Throughout pregnancy, close monitoring of the mother for thrombosis as well as placenta is recommended to ensure blood clots are diagnosed in time for interventions.
- Post partum, often daily injections of low dose low molecular weight heparin (e.g. enoxaparin) and low dose aspirin are prescribed as prophylaxis for several weeks as this is a period where the mother is at higher risk of developing a blood clot.[5]
References
- ↑ Plateletpheresis. Wikipedia. https://en.wikipedia.org/wiki/Plateletpheresis Accessed on November 12, 2015.
- ↑ Prognosis and treatment of essential thrombocythemia. UpToDate.http://www.uptodate.com/contents/prognosis-and-treatment-of-essential-thrombocythemia Accessed on November 12, 2015.
- ↑ Harrison CN et al. Hydroxyurea compared with anagrelide in high-risk essential thrombocythemia. N Engl J Med. 2005;7:33-45. PMID 16000354.
- ↑ Marie-Cecile Valera, Olivier Parant, Christophe Vayssiere, Jean-Francois Arnal & Bernard Payrastre (2011). "Essential thrombocythemia and pregnancy". European journal of obstetrics, gynecology, and reproductive biology. 158 (2): 141–147. doi:10.1016/j.ejogrb.2011.04.040. PMID 21640467. Unknown parameter
|month=ignored (help) - ↑ Essential thrombocythemia. Orphanet journal of rare diseases. http://www.ojrd.com/content/2/1/3 Accessed on November 11, 2015.