Hydrocortisone: Ligand to PXR. Substrate for CYPs 3A4, 3A7, 11 B2. Inducer and inhibitor of CYP 3A4. Several references stating non-porphyrinogenicity. urea: probably not absorbed.

(To be edited, initial data ST OCT 04) Mild glucocorticoid in combination with the waterbinding agent carbamide. Glucocorticoid: South African list: use. Kalman, Bonkovsky: believed to be safe. The Merck Manual: use. Moore MR, Hift RJ: Drugs in acute porphyria. Cell Mol Biol 43:89, 1997: safe. Tschudy DP, Lamon JM: Porphyrin metabolism and the Porphyrias in Bondy BK, Rosenberg LE (eds): Duncan’s Diseases of Metabolism, Philadelphia, WB Saunders 1980, p 939: safe.

Uneventful use reported in 3 patients with acute porphyria.