Dexamethasone Intensol

Concomitant use with amphotericin B may cause hypokalemia and has been associated with cardiac enlargement and congestive heart failure.

Concomitant use may produce severe weakness in patients with myasthenia gravis.

Increased activity of both cyclosporine and dexamethasone may occur with concurrent use; convulsions have been reported.

Patients on digitalis glycosides may be at increased risk of arrhythmias due to dexamethasone-induced hypokalemia.

Dexamethasone may increase blood glucose concentrations, requiring dosage adjustments of antidiabetic agents.

Aminoglutethimide may diminish adrenal suppression by dexamethasone.

Barbiturates induce CYP 3A4 and enhance dexamethasone metabolism, requiring dosage increase.

Carbamazepine induces CYP 3A4 and enhances dexamethasone metabolism, requiring dosage increase.

Cholestyramine may increase the clearance of dexamethasone.

Ephedrine enhances metabolic clearance of dexamethasone, resulting in decreased blood levels and requiring dosage increase.

CYP 3A4 Inhibitors: Concomitant administration of dexamethasone with erythromycin, a moderate CYP 3A4 inhibitor, has the potential to result in increased plasma concentrations of dexamethasone. Co-administration with other drugs that are metabolized by CYP 3A4 (e.g., indinavir, erythromycin) may increase their clearance, resulting in decreased plasma concentration.

Estrogens may decrease hepatic metabolism of dexamethasone, thereby increasing its effect.

Indomethacin has been reported to cause false-negative dexamethasone suppression test results; DST results should be interpreted with caution.

Serum concentrations of isoniazid may be decreased by dexamethasone.

Ketoconazole, a strong CYP3A4 inhibitor, has been reported to decrease the metabolism of certain corticosteroids by up to 60%, leading to increased risk of corticosteroid side effects. In addition, ketoconazole alone can inhibit adrenal corticosteroid synthesis and may cause adrenal insufficiency during corticosteroid withdrawal.

Macrolide antibiotics cause significant decrease in dexamethasone clearance.

Oral contraceptives may decrease hepatic metabolism of dexamethasone, thereby increasing its effect.

Phenytoin induces CYP 3A4 and enhances dexamethasone metabolism, requiring dosage increase.

Rifampin induces CYP 3A4 and enhances dexamethasone metabolism, requiring dosage increase.

Dexamethasone usually inhibits response to warfarin; coagulation indices should be monitored frequently.

Co-administration with other drugs which strongly inhibit CYP 3A4 (e.g., itraconazole, clarithromycin, ritonavir, cobicistat-containing products) may lead to increased plasma concentrations of corticosteroids and potentially increase the risk for systemic corticosteroid side effects.

Co-administration with other drugs that are metabolized by CYP 3A4 (e.g., indinavir, erythromycin) may increase their clearance, resulting in decreased plasma concentration.

Co-administration with other drugs which strongly inhibit CYP 3A4 (e.g., itraconazole, clarithromycin, ritonavir, cobicistat-containing products) may lead to increased plasma concentrations of corticosteroids and potentially increase the risk for systemic corticosteroid side effects.

Co-administration with other drugs which strongly inhibit CYP 3A4 (e.g., itraconazole, clarithromycin, ritonavir, cobicistat-containing products) may lead to increased plasma concentrations of corticosteroids and potentially increase the risk for systemic corticosteroid side effects.

Thalidomide : Co-administration with thalidomide should be employed cautiously, as toxic epidermal necrolysis has been reported with concomitant use.