Aminoglutethimide administered concomitantly with DEPO-PROVERA Sterile Aqueous Suspension may significantly depress the serum concentrations of medroxyprogesterone acetate. DEPO-PROVERA users should be warned of the possibility of decreased efficacy with the use of this or any related drugs.
Medroxyprogesterone acetate is metabolized primarily by hydroxylation via the CYP3A4. Though no formal drug interaction trials have been conducted, concomitant administration of strong CYP3A inhibitors is expected to increase concentrations of medroxyprogesterone acetate, whereas the concomitant administration of strong CYP3A inducers is expected to decrease medroxyprogesterone acetate concentrations. Therefore, coadministration with strong CYP3A inhibitors (e.g., ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, voriconazole) or strong CYP3A inducers (e.g., phenytoin, carbamazepine, rifampin, rifabutin, rifapentin, phenobarbital, St. John's Wort) should be avoided.