The bioavailability of oral methotrexate in children with inflammatory bowel disease.
OBJECTIVE
Methotrexate is used to treat patients with inflammatory bowel disease. Although no available pharmacologic data support the assumption that the bioavailability of methotrexate is diminished in patients with inflammatory bowel disease, most such patients receive methotrexate parenterally.


METHODS
The oral bioavailability of methotrexate was determined in 11 pediatric patients being treated with methotrexate for inflammatory bowel disease. Serial plasma methotrexate concentrations were determined after equal subcutaneous and oral doses of methotrexate.


RESULTS
The mean bioavailability of methotrexate in patients with inflammatory bowel disease was 84% +/- 38%. Interpatient variability in drug exposure was similar after oral and subcutaneous administration.


CONCLUSIONS
The bioavailability of methotrexate in patients with inflammatory bowel disease is no different from that observed in other disease states. Subcutaneous administration of methotrexate does not appear to decrease the interpatient variability in drug exposure. There is no sound pharmacologic basis for favoring administration of methotrexate via the subcutaneous route for patients with inflammatory bowel disease.
Stephens
Michael C
MC
Center for Pediatric IBD, The Children's Hospital of Philadelphia, Pennsylvania, USA.
Baldassano
Robert N
RN
York
Amy
A
Widemann
Brigitte
B
Pitney
Aaron C
AC
Jayaprakash
Nalini
N
Adamson
Peter C
PC
D000284:Administration, Oral; D000293:Adolescent; D019540:Area Under Curve; D001682:Biological Availability; D002648:Child; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood / Q000493:pharmacokinetics*; D015212:Inflammatory Bowel Diseases / Q000097:blood / Q000188:drug therapy / Q000378:metabolism*; D007279:Injections, Subcutaneous; D008297:Male; D008727:Methotrexate / Q000097:blood / Q000493:pharmacokinetics*
D007166:Immunosuppressive Agents; D008727:Methotrexate