[Treatment of essential thrombocythemia with anagrelide: a ten-year experience].
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.
Kornblihtt
Laura I
LI
Instituto de Investigaciones Médicas Alfredo Lanari, Facultad de Medicina, Universidad de Buenos Aires, Argentina.
Vassallu
Patricia S
PS
Heller
Paula
P
Molinas
Felisa C
FC
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
D010975:Platelet Aggregation Inhibitors; D011799:Quinazolines; C021139:anagrelide