Adverse Effects of Phenobarbital on Corticosteroid Metabolism in Patients with Bronchial Asthma

Paper Chromatography prior to Cortisol RIA Allows for Accurate Use of the Dexamethasone Suppression Test in Chronic Renal Failure

“…Accelerated metabolism of dexamethasone in chronic renal failure has been advanced as a possible explanation [9]; however, although levels of dexamethasone after intravenous administration have been reported to be normal, cortisol levels were still incompletely suppressed [5]. Increased hepatic metabolism of dexamethasone with abnormal dexamethasone suppression testing has also been documented in patients on chronic anticonvulsant therapy [10, 11]. In this situation, hydrocortisone-induced suppression of plasma corticosterone has been shown to be a valid alternative to standard dexamethasone testing [12].…”

Stimulatory Effect of Phenobarbital on the Metabolism of the Oral Contraceptive 17α-E thynylestradiol-3-Methyl Ether (Mestranol) by Rat Liver Microsomes

“…Conney, 1967;Conney et al, 1973). Ad ministration of phénobarbital to glucocorticoiddependent asthmatics or administration of rifampicin to a patient with Addison's disease markedly decreased the effectiveness of gluco corticoid therapy and lowered the plasma halflife of glucocorticoids (Brooks et al, 1972;Hunter, 1974, Edwards et al, 1974.…”

The Clinical Consequences of Chronic Hepatic Enzyme Induction by Anticonvulsant Drugs

“…Therapeutic use has been made of this effect by administering phenytoin to patients with Cushing's disease, but the beneficial effect is small (Choi, Werk & Sholiton, 1970). Dexamethasone metabolism is similarly affected, as has been shown in asthmatic patients who were given phenobarbitone in addition for sedative purposes (Brooks, Werk, Ackerman, Sullivan & Thrasher, 1972). The metabolism of other steroid compounds such as androgens and oestrogens is also induced (Kuntzman, 1969), and this may be the reason why epileptic patients develop acne, coarse facies and hirsutes.…”