McCune J S, Liles D, Lindley C
University of North Carolina, School of Pharmacy, Chapel Hill 27599-7360, USA.
Pharmacotherapy. 1997 Jul-Aug;17(4):822-6.
Thrombotic and hemorrhagic events may result from high circulating concentrations of platelets (> 1,000,000/mm3), and measures to reduce the platelet count are indicated in symptomatic or extreme thrombocytosis. The platelet count can be decreased quickly by plasmapheresis, but the effect is transient. Patients with thrombocytosis secondary to a myeloproliferative disease, such as chronic myelogenous leukemia (CML), frequently require more sustained suppression of the platelet count. Hydroxyurea, busulfan, and interferon are used to maintain a lower platelet count but are occasionally ineffective or intolerable. An alternative to these therapies is anagrelide, a quinazolin derivative that was approved by the Food and Drug Administration in March 1997. Because current dosing guidelines for anagrelide are scarce, the dosing method of the Anagrelide Study Group that published the largest study to date on the drug's efficacy in thrombocytosis was followed. Two unexpected episodes of anagrelide-induced thrombocytopenia occurred despite following these dosing methods. This prompted a critical evaluation of the pharmacodynamic response and the appropriateness of anagrelide dosage recommendations. A case of thrombocytosis treated with anagrelide in a patient with CML is described.
血小板循环浓度过高（>1,000,000/mm³）可能导致血栓形成和出血事件，对于有症状的或严重血小板增多症患者，需要采取措施降低血小板计数。血浆置换可迅速降低血小板计数，但效果是短暂的。继发于骨髓增殖性疾病（如慢性粒细胞白血病（CML））的血小板增多症患者，通常需要更持续地抑制血小板计数。羟基脲、白消安和干扰素用于维持较低的血小板计数，但偶尔会无效或无法耐受。这些疗法的替代药物是阿那格雷，一种喹唑啉衍生物，于1997年3月获得美国食品药品监督管理局批准。由于目前关于阿那格雷的给药指南较少，因此遵循了阿那格雷研究组的给药方法，该研究组发表了迄今为止关于该药物治疗血小板增多症疗效的最大规模研究。尽管遵循了这些给药方法，仍发生了两例意外的阿那格雷诱导的血小板减少症。这促使对药效学反应和阿那格雷剂量推荐的合理性进行批判性评估。本文描述了1例CML患者使用阿那格雷治疗血小板增多症的病例。
