<p>Erythromycin, Clarithromycin, Phenobarbital, Phenytoin, Rifampin and Ketoconazole inhibit the metabolism of Methylprednisolone. Estrogens, including With control pills, can increase the effect of corticosteroids by 50%. Cyclosporin reduces the metabolism of Methylprednisolone. while Methylprednisolone reduces the metabolism of Cyclosporin. Methylprednisolone may increase or decrease the effect of blood thinners (e.g. Warfarin). For all these Interactions, the dose of Methylprednisolone may need to be lowered.</p>