The influence of high-dose methotrexate therapy on serum iron.
After 43 cycles of high-dose methotrexate (MTX), the behavior of serum iron was determined. In virtually all cases, typical changes were demonstrated: 8-12 h after termination of treatment there was a sharp increase in serum iron. After 48-60 h, maximum values of 295% (median) of the pretreatment levels were found. Only when the serum MTX had dropped to 6.6 X 10(-8) M, after 62 h (median), did the serum iron level begin to drop; 72 h after termination of treatment the serum iron level had returned to the pretreatment level in only one, and after 108 h, only in 50% of the patients. The marked and persistent rise in serum iron must be considered a consequence of a powerful inhibitory effect of high-dose methotrexate on erythropoiesis. A possible explanation for the particular sensitivity of erythropoiesis to MTX may be the marked storage of MTX, and in particular MTX polyglutamates, in mature erythrocytes and their progenitor cells.
Schalhorn
A
A
Wilmanns
W
W
Koczorek
G E
GE
D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000097:blood / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004920:Erythropoiesis / Q000187:drug effects*; D005260:Female; D006801:Humans; D007501:Iron / Q000097:blood*; D008297:Male; D008727:Methotrexate / Q000009:adverse effects* / Q000097:blood / Q000627:therapeutic use; D008875:Middle Aged; D012516:Osteosarcoma / Q000097:blood / Q000188:drug therapy*
D007501:Iron; D008727:Methotrexate