Megaloblastic anaemia due to excessively prolonged administration of pyrimethamine
Masana, L.; Nubiola, A.R.; Rubiés-Prat, J.
Sangre 26(2): 216-220
1981
ISSN/ISBN: 0036-4355 PMID: 7280928 Document Number: 177020
Pyrimethamine is an antiparasitic drug used in humans because of its effect against paludism and toxoplasmosis. The drug's action is exerted through the inhibition of folate conversion into active forms, namely folinic acid; due to this antifolic effect, pyrimethamine may be capable of inducing hemopoietic changes which do not appear at the usual pharmacological doses. A patient was reported in whom serve megaloblastic anemia with leukopenia and thrombocytopenia developed after prolonged pyrimethamine ingestion. Such blood picture subsided quickly after the drug was discontinued and folinic acid was given for a short time.