title: [Treatment of essential thrombocythemia with anagrelide: a ten-year experience].
abstract: Essential thrombocythemia (ET) is a chronic myeloproliferative syndrome characterized by thrombocythemia and increased megakaryocytes in bone marrow, thrombosis and/or hemorrhagic manifestations. We report here a ten-year experience in the treatment of ET with anagrelide (A), a non mutagenic drug that inhibits megakaryocyte maturation. Between April 1991 and June 2001, 54 ET patients were included with platelet counts > 900 x 10(9)/l in asymptomatic cases and > 600 x 10(9)/l in symptomatic ones. Age at diagnosis was 39 years (11-83). Previously 30 patients had received treatment with hydroxyurea, alpha INF, busulfan and/or 32P. At diagnosis 18 patients had microvascular obstruction, 7 thrombosis, 8 hemorrhagic manifestations and 3 both hemorrhage and thrombosis. Platelet counts at diagnosis were 1200 x 10(9)/l (600-3472) and before A 995 x 10(9)/l (520-2206). The follow-up from diagnosis was 68 months (9-172) and with A treatment 34 months (2-100). The A dose during the first week of treatment was 2.5 mg/d (1-3) and at maintenance 1.5 mg/d (1-3). Complete response was obtained in 96.3% cases, 77% with platelet counts < 400 x 10(9)/l, and 18.5% < 600 x 10(9)/l. The median time to obtain a complete response was 14 days. Transient adverse effects were present in 66% of patients (headache, nausea, abdominal distention, palpitation and edema). Mild to moderate anemia developed within 2-8 months in 40% of patients. During treatment 8 patients had microvascular obstruction with platelet counts over 400 x 10(9)/l and 7 with normal values. One patient developed myelofibrosis. Five patients died for reasons unrelated to ET. In conclusion, anagrelide was effective in reducing platelet counts and preventing mayor thrombotic events.
authors.affiliation: Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
authors.forename: Laura I
authors.initials: LI
authors.lastname: Kornblihtt
authors.forename: Patricia S
authors.initials: PS
authors.lastname: Vassallu
authors.forename: Paula
authors.initials: P
authors.lastname: Heller
authors.forename: Felisa C
authors.initials: FC
authors.lastname: Molinas
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010976:Platelet Count; D011799:Quinazolines / Q000627:therapeutic use*; D013920:Thrombocythemia, Essential / Q000097:blood / Q000188:drug therapy*; D016896:Treatment Outcome
chemical_list: D010975:Platelet Aggregation Inhibitors; D011799:Quinazolines; C021139:anagrelide