What is known about the duration of megaloblastic anemia during treatment with methotrexate?/nA 67-

Fråga: What is known about the duration of megaloblastic anemia during treatment with methotrexate?

A 67-year-old woman has been treated with methotrexate for six to seven years due to rheumatoid arthritis. The patient has had episodes of anemia which have regressed spontaneously. In December 1996 hemoglobin was lower(61 g/L) than previously (normal range 113-139 g/L). November 7, 1996, mean corpuscular volume 110 (normal range 76-96 femtoliter). Methotrexate was withdrawn on December 10, 1996. In January 7, 1997 mean corpuscular volume was 97. On May 13 the patient still had anemia (Hb 88) and mean corpuscular volume 87 was within normal range.

Sammanfattning: Megaloblastic anemia induced by methotrexate would be normalized within one to two months after withdrawal of methotrexate and treatment with folate therapy.

Svar: Megaloblastic anemia is an expected adverse reaction in patients treated with methotrexate. No information is found concerning duration of megaloblastic anemia after discontinued treatment with methotrexate. However, after withdrawal and replacement therapy with folate, the hematological response with reticulocytosis after about four days followed by correction of the anemia over the next one to two months, can be expected (1). 1 Harrison´s, Principles of Internal Medicine, 1994; 11th ed: 1503