EFFECT OF FOOD ON THE BIOAVAILABILITY OF LOW-DOSE METHOTREXATE IN PATIENTS WITH RHEUMATOID-ARTHRITIS

Objective. To evaluate the influence of food on the bioavailability of an oral dose of methotrexate in patients with rheumatoid arthritis. Methods. 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. Results. Food reduced the peak concentration, from a mean of 0.71-mu-moles/liter to 0.49-mu-moles/liter (P < 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. Conclusion. Bioavailability of oral methotrexate shows marked interindividual variation but is not affected by the presence of food.