RT Journal Article SR Electronic T1 Azathioprine-induced severe anemia potentiated by the concurrent use of allopurinol JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E94 OP E97 DO 10.1503/cmaj.201022 VO 193 IS 3 A1 Lorenzo Madrazo A1 Emily Jones A1 Cyrus C. Hsia YR 2021 UL http://www.cmaj.ca/content/193/3/E94.abstract