Cyclosporine absorption in intestinal transplantation.

The absorption of oral cyclosporine (CsA) was studied in a canine small intestinal transplantation model. Absorption of CsA was almost absent in bowel-resected dogs. Autotransplanted dogs showed a persisting malabsorption of CsA (mean peak of 687 +/- 348 ng/ml vs. 1683 +/- 154 ng/ml in control dogs). Allotransplanted dogs with normal graft histology showed a similar malabsorption (mean increase in CsA level: 833 ng/ml), whereas allotransplanted dogs with rejection of the graft showed a markedly decreased absorption (mean increase: 368 +/- 31 ng/ml). In two autotransplanted dogs pretreated with olive oil alone, CsA absorption increased over four weeks to a mean peak of 2215 +/- 5 ng/ml. We conclude that oral CsA is absorbed through the small intestine. Absorption of CsA is decreased after autotransplantation and allotransplantation, and rejection of the graft impedes it further. Regular administration of olive oil alone enhances absorption of oral CsA in a canine model.