Estrogen interaction with other drugs

Ketoconazole can lead to reduced clearance of CS and a mild increase in levels (62,66,67). In addition, patients with significant liver or renal failure, age older than 65 years (68), or women receiving exogenous estrogen have increased unbound concentrations of prednisolone (69). Conversely, hyperthyroid patients have lower levels (70). There is one case report of an increased prothrombin time occurring in a patient on a stable dose of coumadin who subsequently received prednisone (71). This interaction seems rare and may be overshadowed by other drugs and events in the patient. Troleandomycin, a macrolide, has been shown to reduce clearance of methylprednisolone, but not prednisone (72). 

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