Bioavailability of hydrocortisone retention enemas in normal subjects

The bioavailability of two commercial formulations of hydrocortisone rectal enemas, Rectoid and Cortenema, was determined in 12 normal volunteers. Relative to an intravenous dose, 50--90% of a dose given rectally was available to the systemic circulation in most subjects provided the retention time exceeded eight hours. The bioavailability and retention times of both enemas were similar. The results suggest that the likelihood for adrenal suppression from hydrocortisone rectal enemas is similar to that resulting from equal doses of oral hydrocortisone.