Development of acute myocardial infarction in a young female patient with essential thrombocythemia treated with anagrelide: a case report

Essential thrombocythemia (ET) is a chronic myeloproliferative disorder with a prolonged clinical course. Since this disorder is considered to be at increased risk of thromboembolism, therapy is mainly focused on the decreased risk of thrombohemorrhagic events by use of cytotoxic agents. Anagrelide is a phosphodiesterase III inhibitor which is utilized in the treatment of ET for the reduction of platelets. However, patients treated with anagrelide might experience cardiovascular adverse effects including myocardial infarction (MI), although these events are rare. Herein, we report a case of a 30-year-old female with well controlled ET by anagrelide, who eventually developed an acute non-ST elevation myocardial infarction (MI). There has no found any cardiovascular risk factors in this ET patient, strongly suggesting that anagrelide might be the cause of MI. Therefore, cardiovascular function should be monitored in those patients prescribed with anagrelide.

Drug-Induced Dilated Cardiomyopathy Associated with Anagrelide

Anagrelide is an effective drug for essential thrombocythaemia, and its adverse cardiovascular effects are relatively rarely reported. We experienced a 73 year-old man with essential thrombocythaemia developed anagrelide-induced dilated cardiomyopathy. After discontinuation of anagrelide, the patient's left ventricular systolic function was completely recovered.

The Efficacy and Adverse Effect of Hydroxyurea as Compared with Anagrelide in Essential Thrombocythemia

BACKGROUND: Although the platelet count may not always correlate with the risk of thrombosis, there is evidence that a strict control of the platelet count decreases the incidence of thrombotic and hemorrhagic complications. However, it is difficult to select an appropriate platelet-lowering agent. This retrospective study was performed to assess the efficacy and adverse effect of the use of hydroxyurea and anagrelide for patients with essential thrombocythemia. METHODS: Sixty patients with essential thrombocythemia received either hydroxyurea (n=30) or anagrelide (n=30). Early responses and adverse effects of hydroxyurea and anagrelide in the patients were retrospectively analyzed. RESULTS: Treatment with anagrelide or hydroxyurea resulted in a rapid decrease of the platelet count within two weeks. The response rates after treatment with hydroxyurea and anagrelide were 83% and 77%, respectively. As compared with patients treated with hydroxyurea, patients treated with anagrelide presented with adverse effects such as headache palpitation was also frequently noticed (P=0.001). However, serious hemorrhage (n=2) and transformation to leukemia (n=1) occurred in patients treated with hydroxyurea. CONCLUSION: Both anagrelide and hydroxyurea were effective and well-tolerated agents for the reduction of the platelet count. Long-term efficacy and adverse effects of the drugs remain to be determined.

Treatment of Children with Anagrelide for Essential Thrombocythemia / 대한소아혈액종양학회지

PURPOSE: Essential thrombocythemia (ET) in children is a rare myeloproliferative disease characterized by persistent elevation of platelets and is associated with an increased risk of thrombohemorrhagic complications. For patients with risk factors, cytoreductive therapy is important to reduce the risk for thrombotic or hemorrhagic events. However, the frequent side effects and the carcinogenic potential of many cytoreductive agents, such as hydroxyurea, limit their use, especially in younger patients. Anagrelide has selective activity against platelet production as well as tolerable toxicity, noncarcinogenic effect and the advantage of oral administration. But, the experience with anagrelide in pediatric patients with ET is limited. METHODS: Four children were diagnosed as ET according to the criteria of the Polycythemia Vera Study Group, at the Department of Pediatrics, Kyungpook National University Hospital in Daegu, Korea from January 1998 to February 2004. After informed consent was obtained from the parents, therapy with anagrelide (induction dose 1~1.5 mg/day, maintenance dose 1 mg/day) was started in three of the four children who had been treated with hydroxyurea. RESULTS: All children had responded well to the anagrelide therapy without significant side effect. CONCLUSION: Anagrelide, a noncarcinogenic agent, seems to be a promising alternative to conventional cytoreductive treatment for children with ET. Additional experience with more asymptomatic and symptomatic children with ET should be reported, with close monitoring of the treated children with anagrelide for early and late side effects.

Therapeutic Efficacy of Anagrelide for Thrombocytosis / 대한혈액학회지

BACKGROUND: Thrombocytosis can result in life-threatening thrombotic or hemorrhagic events. Anagrelide acts exclusively on megakaryocytes and has been reported as an useful agent in controlling thromobocytosis associated with chronic myeloproliferative disorders. METHODS: Seven patients with essential thrombocythemia and three with chronic myelogenous leukemia were enrolled and early responses and adverse effects of anagrelide were retrospectively analyzed. The drug was started with a dose of 2 mg/day with increases of 0.5 mg/day every 5~7 days as needed. RESULTS: Anagrelide in starting doses of 2 mg/day reduced the platelet count by 50%, or to less than 600,000/mm3, for at least 28 days in 7 of the 9 (78%) evaluable patients. Adverse effects of the drug were observed in 5 patients and generally well tolerated; headache in 4, gastrointestinal troubles in 2, palpitations and chest tightness in 1, and tinnitus in 1. Changes in hemoglobin or white blood cell counts in peripheral blood were minimal and tolerable. CONCLUSION: The present study shows that anagrelide is a useful platelet-lowering agent in whom hydroxyurea or interferon has failed. Long-term efficacy and adverse effects of the drug remain to be determined.