title: The absorption and conjugation of methyldopa in patients with coeliac and Crohn's diseases during treatment.
abstract: The absorption and elimination of a single 500 mg dose of methyldopa has been studied after oral administration to 10 normal volunteers, 10 patients with coeliac disease, who were on a gluten-free diet, and to five patients with Crohn's disease. In patients with Crohn's disease the percentage of the dose recovered in urine (24%) was about one-half of normal (50%). This decreased absorption was associated with reduced plasma concentrations of both free and conjugated methyldopa and a decreased pharmacological response. In patients with coeliac disease the percentage of dose recovered in urine (43%) was similar to normals, indicating a normal absorption of the drug. However, the plasma concentrations of both free and conjugated methyldopa were significantly higher than normal, although there was no increase in drug-related effects. These findings confirm the importance of using indices other than drug plasma concentrations in the assessment of bioavailability in disease states.
mesh_terms: D000328:Adult; D000368:Aged; D001682:Biological Availability; D001711:Biotransformation; D002446:Celiac Disease / Q000378:metabolism*; D003424:Crohn Disease / Q000378:metabolism*; D005260:Female; D006207:Half-Life; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D008750:Methyldopa / Q000378:metabolism* / Q000627:therapeutic use; D008875:Middle Aged
chemical_list: D008750:Methyldopa