Corticosteroids Aminoglutethimide

Prednisolone [Corticosteroid] [See Steroids and Table VI-1] Interactions T Effects W/ clarithromycin, erythromycin, estrogen, ketoconazole, OCPs, troleandomycin X effects W/ antacids, aminoglutethimide, barbiturates, cholestyramine, colestipol, phenytoin, rifampin X effects OF anticoagulants, hypoglycemics, INH, salicylates, vaccine toxoids EMS Infxns may be masked OD May cause wt gain, T hair growth, acne, HTN, peripheral edema, and sore muscles symptomatic and supportive... 

Aminoglutethimide is a nonsteroidal inhibitor of corticosteroid biosynthesis. It results in decreased production of endogenous estrogens, androgens, and cortisol. It has been used to treat patients with breast cancer, and off-label uses include treatment of prostate cancer. Because this is a rela-... 

Androgens Fluoxymesterone Testosterone Androgen antagonists Bicalutamide Flutamide Ketoconazole Nilutamide Aromatase inhibitors Aminoglutethimide Anastrazole Exemestane Letrozole Corticosteroids Dexamethasone Prednisone Estrogens Diethylstilbesterol Estradiol... 

Aminoglutethimide, rifampin, barbiturates, charcoal, ketoconazole, smoking (cigarettes and marijuana), sulfinpyrazone, and sympathomimetics (beta-agonists)—all decrease the plasma levels of theophylline, whereas allopu-rinol, beta-blockers (nonselective), calcium-channel blockers, cimetidine, contraceptives, corticosteroids, disulfiram, ephedrine, interferon, macrolides, mexiletine, quinolones, and thiabendazole all increase the plasma levels of theophylline. 

Information is limited but the interaction between dexamethasone and aminoglutethimide is established. The reduction in the serum corticosteroid levels can be enough to reduce or even abolish the effects of corticosteroid replacement therapy or to cause loss of control of a disease condition. This has been successfully accommodated by increasing the dosage of the dexamethasone. Hydrocortisone is routinely used with aminoglutethimide as replacement therapy, and would seem to be a suitable alternative to dexamethasone, where clinically appropriate. Other synthetic corticosteroids are predicted to interact in the same way as dexamethasone, but this needs confirmation. 

---