Pediatric Thrombocytosis Medication

Updated: Aug 17, 2020
  • Author: Susumu Inoue, MD; Chief Editor: Hassan M Yaish, MD  more...
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Medication Summary

In a child with reactive thrombocytosis, drug therapy is not required. Thrombohemorrhagic complications are exceedingly rare. To date, no studies have demonstrated a benefit of prophylactic use of antithrombotic or antiplatelet agents. In general, use of these drugs is not warranted. One exception in which antithrombotic or antiplatelet drugs should be used is for Kawasaki syndrome. A clear guideline for aspirin use with this syndrome has been established (see Kawasaki Disease).

Symptomatic patients with essential thrombocytosis (ET) should receive treatment to lower their platelet count. For pediatric use, anagrelide or hydroxyurea is recommended. In a study by Harrison et al, adult patients (median age, about 60 y) were randomly assigned to receive low-dose aspirin plus hydroxyurea or anagrelide. [51] Significantly more patients in the anagrelide arm than in the hydroxyurea arm reached the study endpoint. The authors concluded that hydroxyurea plus aspirin was more effective than anagrelide plus aspirin in preventing complications in adults with ET.

Radioactive phosphorus should not be used for young patients because of its carcinogenic potential.

Use of pharmacologic agents to prevent thrombotic complications in primary or ET is controversial, even in the internal medicine literature, because no laboratory studies offer predictive value in terms of the risk of thrombosis or hemorrhage. Tefferi et al recommend their use in only patients older than 60 years, individuals with a history of thrombosis, or persons with cardiovascular risk factors, virtually eliminating pediatric patients. [46]

Patients who do develop a thrombus should be treated appropriately (see Thromboembolism).


Agents to reduce platelet count and reduce platelet function

Class Summary

These agents are used to treat thrombotic complications and to prevent thrombosis (in some cases) in patients with an established diagnosis of ET.

Anagrelide (Agrylin)

Specifically lowers platelet count, presumably by reducing megakaryocyte size and ploidy. Not FDA approved for use in patients < 16 y, but a small number of pediatric patients have been treated without significant adverse effects. Long-term adverse effects totally unknown; therefore, clearly positive benefit-risk ratio must be shown before administering drug to any child.


Cytoreductive agents

Class Summary

These agents should be used only in patients with thrombotic complications (or in some in need of prevention of thrombosis) with an established diagnosis of primary thrombocythemia.

Hydroxyurea (Hydrea)

Inhibits DNA synthesis (RNA reductase inhibitor), reducing all 3 blood cell counts.