title: Hydroxycarbamide associated platelet count oscillations in a patient with polycythaemia vera. A case report and review of the literature.
abstract: We describe an unusual case of oscillating platelet counts in a patient with polycythaemia vera. Following commencement of cytoreductive hydroxycarbamide therapy, episodes of thrombocytopenia were followed regularly by thrombocytosis. Platelet counts fluctuated periodically between approximately 200 and 800 x 109/l, with a 28 day cycle duration. Frequent adjustment of the hydroxycarbamide dose was not successful in preventing the oscillations in platelet count. In contrast, maintenance of a constant dose led to a gradual damping of the cycles and thus termination of the large oscillations. The case further implicates hydroxycarbamide as a potential cause of cyclic variations in platelet counts, and demonstrates that cessation of this drug is not always necessary in order to treat this phenomenon.
authors.affiliation: Department of Haematology, Manchester Royal Infirmary, UK.
authors.forename: John
authors.initials: J
authors.lastname: Burthem
authors.forename: Mohammed Suhail
authors.initials: MS
authors.lastname: Chaudhry
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D006918:Hydroxyurea / Q000008:administration & dosage*; D008875:Middle Aged; D010976:Platelet Count; D011087:Polycythemia Vera / Q000097:blood* / Q000188:drug therapy*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D006918:Hydroxyurea