Background: Essential thrombocythaemia is a chronic myeloproliferative disease characterised by persistent thrombocytosis, i.e. platelet count > 600 x 10(9)/l and an increased risk of thromboembolic complications. Anagrelide may be used as a platelet-lowering agent in patients with essential thrombocythaemia.
Material and methods: At Akershus Central Hospital, ten patients below 60 years of age have been treated with anagrelide in the period 1997 through 2000. Patients were identified and data obtained from hospital files. Nine patients had been treated previously, mainly with hydroxyurea. Three patients were asymptomatic.
Results: Anagrelide was introduced with gradually higher dosage, while the dosage of hydroxyurea was gradually reduced. Four patients experienced slight and transient headache, five palpitations, and two diarrhoea. One patient had to limit the dose because of palpitations. The medication was discontinued in two patients because of side effects. The seven patients who tolerated the medication well, acquired platelet counts below 500 x 10(9)/l. No vascular complications have occurred.
Interpretation: Anagrelide is an efficacious drug in essential thrombocythaemia with relatively few side effects. Anagrelide should be considered a treatment of choice in patients below 60 years of age with essential thrombocythaemia.