To evaluate the influence of food on the bioavailability of an oral dose of methotrexate in patients with rheumatoid arthritis.
Methotrexate (15 mg) was given intravenously and orally, with or without a meal, to 10 patients. Blood samples were drawn at specific intervals to evaluate drug levels.
Food reduced the peak concentration, from a mean of 0.71 mumoles/liter to 0.49 mumoles/liter (P less than 0.02), and slightly increased the time to peak concentration, from a mean of 1.3 hours to 2.0 hours. Bioavailability was highly variable (range 28-94%) but was not affected by food intake.
Bioavailability of oral methotrexate shows marked interindividual variation but is not affected by the presence of food.