BACKGROUND: Oral @entity1499 and @entity1501 are partly absorbed by a common intestinal transporter. AIM: : To determine the relative bioavailability of oral low-dose @entity1499 administered with and without concomitant @entity1501 vs. subcutaneous administration in @entity1 with stable @entity30 . METHODS: Ten @entity1 were randomized to receive their regular maintenance dose of @entity1499 (15-25 mg) for three consecutive weeks: orally, orally with 5 mg @entity1501 or subcutaneously. Blood samples were drawn at specified intervals during 24 h, and @entity1499 levels were determined by fluorescence immunoassay. Areas under the curve extrapolated to infinity (AUC infinity ) were compared between the three routes. RESULTS: The geometric mean AUC infinity values (95% confidence intervals) were 360 nmol x h/L (301-430 nmol x h/L), 261 nmol x h/L (214-318 nmol x h/L) and 281 nmol x h/L (209-377 nmol x h/L) per milligram of @entity1499 administered for subcutaneous, oral and oral with @entity1501 administration, respectively (P < 0.05 and P < 0.01 for oral with @entity1501 and oral vs. subcutaneous administration, respectively). The geometric mean relative bioavailabilities (95% confidence intervals) were 0.73 (0.62-0.86) and 0.77 (0.60-0.99) for oral and oral with @entity1501 administration, respectively (difference not significant). CONCLUSIONS: In @entity1 with stable @entity30 , the oral bioavailability of @entity1499 is highly variable and averages 73% of that of subcutaneous administration. Concomitant @entity1501 has no significant effect on the bioavailability. Dose adjustments based on individual pharmacokinetic assessment should be considered when switching @entity1 from parenteral to oral therapy.

Bioavailability of oral vs. subcutaneous low-dose XXXX in @entity1 with @entity30 .

@entity1501 :: ('MESH:D005492', 'Chemical') :: ['folic acid'] @entity1 :: ('9606', 'Species') :: ['patients'] @entity1499 :: ('MESH:D008727', 'Chemical') :: ['methotrexate'] @entity30 :: ('MESH:D003424', 'Disease') :: ["Crohn's disease"]
@entity1499 :: (MESH:D008727,Chemical) :: ['methotrexate']
